Struct sqlstate_inline::Class
source · pub struct Class { /* private fields */ }
Expand description
Implementations§
source§impl Class
impl Class
sourcepub const fn from_str(value: &str) -> Result<Self, ParseError>
pub const fn from_str(value: &str) -> Result<Self, ParseError>
sourcepub const fn from_bytes(value: &[u8]) -> Result<Self, ParseError>
pub const fn from_bytes(value: &[u8]) -> Result<Self, ParseError>
sourcepub const fn from_byte_array(value: [u8; 2]) -> Result<Self, ParseError>
pub const fn from_byte_array(value: [u8; 2]) -> Result<Self, ParseError>
sourcepub const fn category(&self) -> Category
pub const fn category(&self) -> Category
Returns the general category for this code class.
Examples
let class = Class::CONNECTION_EXCEPTION;
assert_eq!(class.category(), Category::Exception);
sourcepub const fn contains(&self, sqlstate: SqlState) -> bool
pub const fn contains(&self, sqlstate: SqlState) -> bool
Returns whether a SQLSTATE is in this class.
Examples
let connection_refused = SqlState("08001");
let syntax_error = SqlState("42000");
let class = Class::CONNECTION_EXCEPTION;
assert_eq!(class.contains(connection_refused), true);
assert_eq!(class.contains(syntax_error), false);
sourcepub const fn is_implementation_specific(&self) -> bool
pub const fn is_implementation_specific(&self) -> bool
Returns whether this class is implementation-specific and not reserved for standard conditions.
All classes starting with 5
-9
or I
-Z
are implementation-specific.
Examples
let class = Class::CONNECTION_EXCEPTION;
assert_eq!(class.is_implementation_specific(), false);
let class = Class::PGSQL_OPERATOR_INTERVENTION;
assert_eq!(class.is_implementation_specific(), true);
let class = Class("XR");
assert_eq!(class.is_implementation_specific(), true);
source§impl Class
impl Class
sourcepub const SUCCESSFUL_COMPLETION: Self = _
pub const SUCCESSFUL_COMPLETION: Self = _
Class 00
: Successful completion
sourcepub const DYNAMIC_SQL_ERROR: Self = _
pub const DYNAMIC_SQL_ERROR: Self = _
Class 07
: Dynamic SQL error
sourcepub const CONNECTION_EXCEPTION: Self = _
pub const CONNECTION_EXCEPTION: Self = _
Class 08
: Connection exception
sourcepub const TRIGGERED_ACTION_EXCEPTION: Self = _
pub const TRIGGERED_ACTION_EXCEPTION: Self = _
Class 09
: Triggered action exception
sourcepub const FEATURE_NOT_SUPPORTED: Self = _
pub const FEATURE_NOT_SUPPORTED: Self = _
Class 0A
: Feature not supported
sourcepub const INVALID_TARGET_TYPE_SPEC: Self = _
pub const INVALID_TARGET_TYPE_SPEC: Self = _
Class 0D
: Invalid target type specification
sourcepub const INVALID_SCHEMA_NAME_LIST_SPEC: Self = _
pub const INVALID_SCHEMA_NAME_LIST_SPEC: Self = _
Class 0E
: Invalid schema name list specification
sourcepub const LOCATOR_EXCEPTION: Self = _
pub const LOCATOR_EXCEPTION: Self = _
Class 0F
: Locator exception
sourcepub const RESIGNAL_WHEN_HANDLER_NOT_ACTIVE: Self = _
pub const RESIGNAL_WHEN_HANDLER_NOT_ACTIVE: Self = _
Class 0K
: Resignal when handler not active (SQL/PSM)
sourcepub const INVALID_GRANTOR: Self = _
pub const INVALID_GRANTOR: Self = _
Class 0L
: Invalid grantor
sourcepub const INVALID_SQL_INVOKED_PROCEDURE_REF: Self = _
pub const INVALID_SQL_INVOKED_PROCEDURE_REF: Self = _
Class 0M
: Invalid SQL-invoked procedure reference
sourcepub const SQL_XML_MAPPING_ERROR: Self = _
pub const SQL_XML_MAPPING_ERROR: Self = _
Class 0N
: SQL/XML mapping error (SQL/XML)
sourcepub const INVALID_ROLE_SPEC: Self = _
pub const INVALID_ROLE_SPEC: Self = _
Class 0P
: Invalid role specification
sourcepub const INVALID_TRANSFORM_GROUP_NAME_SPEC: Self = _
pub const INVALID_TRANSFORM_GROUP_NAME_SPEC: Self = _
Class 0S
: Invalid transform group name specification
sourcepub const TARGET_TABLE_DISAGREES_WITH_CURSOR_SPEC: Self = _
pub const TARGET_TABLE_DISAGREES_WITH_CURSOR_SPEC: Self = _
Class 0T
: Target table disagrees with cursor specification
sourcepub const ATTEMPT_TO_ASSIGN_TO_NON_UPDATABLE_COLUMN: Self = _
pub const ATTEMPT_TO_ASSIGN_TO_NON_UPDATABLE_COLUMN: Self = _
Class 0U
: Attempt to assign to non-updatable column
sourcepub const ATTEMPT_TO_ASSSIGN_TO_ORDERING_COLUMN: Self = _
pub const ATTEMPT_TO_ASSSIGN_TO_ORDERING_COLUMN: Self = _
Class 0V
: Attempt to assign to ordering column
sourcepub const PROHIBITED_STATEMENT_DURING_TRIGGER_EXEC: Self = _
pub const PROHIBITED_STATEMENT_DURING_TRIGGER_EXEC: Self = _
Class 0W
: Prohibited statement encoutered during trigger execution
sourcepub const INVALID_FOREIGN_SERVER_SPEC: Self = _
pub const INVALID_FOREIGN_SERVER_SPEC: Self = _
Class 0X
: Invalid foreign server specification (SQL/MED)
sourcepub const PASSTHROUGH_SPECIFIC_CONDITION: Self = _
pub const PASSTHROUGH_SPECIFIC_CONDITION: Self = _
Class 0Y
: Pass-through specific condition (SQL/MED)
sourcepub const DIAGNOSTICS_EXCEPTION: Self = _
pub const DIAGNOSTICS_EXCEPTION: Self = _
Class 0Z
: Diagnostics exception
sourcepub const XQUERY_ERROR: Self = _
pub const XQUERY_ERROR: Self = _
Class 10
: XQuery error (SQL/XML)
sourcepub const CASE_NOT_FOUND_FOR_CASE_STATEMENT: Self = _
pub const CASE_NOT_FOUND_FOR_CASE_STATEMENT: Self = _
Class 20
: Case not found for case statement (SQL/PSM)
sourcepub const CARDINALITY_VIOLATION: Self = _
pub const CARDINALITY_VIOLATION: Self = _
Class 21
: Cardinality violation
Subquery row count mismatch, column count mismatch, etc.
sourcepub const DATA_EXCEPTION: Self = _
pub const DATA_EXCEPTION: Self = _
Class 22
: Data exception
Overflow, truncation, out of range, etc.
sourcepub const INTEGRITY_CONSTRAINT_VIOLATION: Self = _
pub const INTEGRITY_CONSTRAINT_VIOLATION: Self = _
Class 23
: Integrity constraint violation
RESTRICT
violation, foreign key constraint violation, etc.
sourcepub const INVALID_CURSOR_STATE: Self = _
pub const INVALID_CURSOR_STATE: Self = _
Class 24
: Invalid cursor state
sourcepub const INVALID_TRANSACTION_STATE: Self = _
pub const INVALID_TRANSACTION_STATE: Self = _
Class 25
: Invalid transaction state
sourcepub const INVALID_SQL_STATEMENT_NAME: Self = _
pub const INVALID_SQL_STATEMENT_NAME: Self = _
Class 26
: Invalid SQL statement name
sourcepub const TRIGGERED_DATA_CHANGE_VIOLATION: Self = _
pub const TRIGGERED_DATA_CHANGE_VIOLATION: Self = _
Class 27
: Invalid SQL statement name
sourcepub const INVALID_AUTHORIZATION_SPEC: Self = _
pub const INVALID_AUTHORIZATION_SPEC: Self = _
Class 28
: Invalid authorization specification
sourcepub const DEPENDENT_PRIVILEGE_DESCRIPTORS_STILL_EXIST: Self = _
pub const DEPENDENT_PRIVILEGE_DESCRIPTORS_STILL_EXIST: Self = _
Class 2B
: Dependent privilege descriptors still exist
sourcepub const INVALID_CHARACTER_SET_NAME: Self = _
pub const INVALID_CHARACTER_SET_NAME: Self = _
Class 2C
: Invalid character set name
sourcepub const INVALID_TRANSACTION_TERMINATION: Self = _
pub const INVALID_TRANSACTION_TERMINATION: Self = _
Class 2D
: Invalid transaction termination
sourcepub const INVALID_CONNECTION_NAME: Self = _
pub const INVALID_CONNECTION_NAME: Self = _
Class 2E
: Invalid connection name
sourcepub const SQL_ROUTINE_EXCEPTION: Self = _
pub const SQL_ROUTINE_EXCEPTION: Self = _
Class 2F
: SQL routine exception
sourcepub const INVALID_COLLATION_NAME: Self = _
pub const INVALID_COLLATION_NAME: Self = _
Class 2H
: Invalid collation name
sourcepub const INVALID_SQL_STATEMENT_IDENTIFIER: Self = _
pub const INVALID_SQL_STATEMENT_IDENTIFIER: Self = _
Class 30
: Invalid SQL statement identifier
sourcepub const INVALID_SQL_DESCRIPTOR_NAME: Self = _
pub const INVALID_SQL_DESCRIPTOR_NAME: Self = _
Class 33
: Invalid SQL descriptor name
sourcepub const INVALID_CURSOR_NAME: Self = _
pub const INVALID_CURSOR_NAME: Self = _
Class 34
: Invalid cursor name
sourcepub const INVALID_CONNECTION_NUMBER: Self = _
pub const INVALID_CONNECTION_NUMBER: Self = _
Class 35
: Invalid connection number
sourcepub const CURSOR_SENSITIVITY_EXCEPTION: Self = _
pub const CURSOR_SENSITIVITY_EXCEPTION: Self = _
Class 36
: Cursor sensitivity exception
sourcepub const EXTERNAL_ROUTINE_EXCEPTION: Self = _
pub const EXTERNAL_ROUTINE_EXCEPTION: Self = _
Class 38
: External routine exception
sourcepub const EXTERNAL_ROUTINE_INVOCATION_EXCEPTION: Self = _
pub const EXTERNAL_ROUTINE_INVOCATION_EXCEPTION: Self = _
Class 39
: External routine invocation exception
sourcepub const SAVEPOINT_EXCEPTION: Self = _
pub const SAVEPOINT_EXCEPTION: Self = _
Class 3B
: External routine invocation exception
sourcepub const AMBIGUOUS_CURSOR_NAME: Self = _
pub const AMBIGUOUS_CURSOR_NAME: Self = _
Class 3C
: Ambiguous cursor name
sourcepub const INVALID_CATALOG_NAME: Self = _
pub const INVALID_CATALOG_NAME: Self = _
Class 3D
: Invalid catalog name
Empty or invalid database name, etc.
sourcepub const INVALID_SCHEMA_NAME: Self = _
pub const INVALID_SCHEMA_NAME: Self = _
Class 3F
: Invalid schema name
sourcepub const TRANSACTION_ROLLBACK: Self = _
pub const TRANSACTION_ROLLBACK: Self = _
Class 40
: Transaction rollback
sourcepub const SYNTAX_ERROR_OR_ACCESS_RULE_VIOLATION: Self = _
pub const SYNTAX_ERROR_OR_ACCESS_RULE_VIOLATION: Self = _
Class 42
: Syntax error or access rule violation
Includes SQL query syntax errors, miscellaneous query errors, and access right violations.
sourcepub const WITH_CHECK_OPTION_VIOLATION: Self = _
pub const WITH_CHECK_OPTION_VIOLATION: Self = _
Class 44
: With check option violation
sourcepub const UNHANDLED_USER_DEFINED_EXCEPTION: Self = _
pub const UNHANDLED_USER_DEFINED_EXCEPTION: Self = _
Class 45
: Unhandled user-defined exception (SQL/PSM)
sourcepub const OLB_SPECIFIC_ERROR: Self = _
pub const OLB_SPECIFIC_ERROR: Self = _
Class 46
: OLB-specific error (SQL/OLB)
Includes Java DDL errors from SQL/JRT.
sourcepub const DATALINK_EXCEPTION: Self = _
pub const DATALINK_EXCEPTION: Self = _
Class HW
: Datalink exception (SQL/MED)
sourcepub const FDW_SPECIFIC_CONDITION: Self = _
pub const FDW_SPECIFIC_CONDITION: Self = _
Class HV
: FDW-specific condition (SQL/MED)
sourcepub const CLI_SPECIFIC_CONDITION: Self = _
pub const CLI_SPECIFIC_CONDITION: Self = _
Class HY
: CLI-specific condition (SQL/CLI)
CLI stands for “Call-Level Interface”. This mainly subsumes API errors
source§impl Class
impl Class
sourcepub const DB2_INVALID_APPLICATION_STATE: Self = _
pub const DB2_INVALID_APPLICATION_STATE: Self = _
DB2-specific: Class 51
: Invalid application state
sourcepub const DB2_INVALID_OPERAND_OR_INCONSISTENT_SPEC: Self = _
pub const DB2_INVALID_OPERAND_OR_INCONSISTENT_SPEC: Self = _
DB2-specific: Class 53
: Invalid operand or inconsistent specification
sourcepub const DB2_SQL_OR_PRODUCT_LIMIT_EXCEEDED: Self = _
pub const DB2_SQL_OR_PRODUCT_LIMIT_EXCEEDED: Self = _
DB2-specific: Class 54
: SQL or product limit exceeded
sourcepub const DB2_OBJECT_NOT_IN_PREREQUISITE_STATE: Self = _
pub const DB2_OBJECT_NOT_IN_PREREQUISITE_STATE: Self = _
DB2-specific: Class 55
: Object not in prerequisite state
sourcepub const DB2_MISCELLANEOUS_SQL_OR_PRODUCT_ERROR: Self = _
pub const DB2_MISCELLANEOUS_SQL_OR_PRODUCT_ERROR: Self = _
DB2-specific: Class 56
: Miscellaneous SQL or product error
sourcepub const DB2_RESOURCE_NOT_AVAILABLE_OR_OPERATOR_INTERVENTION: Self = _
pub const DB2_RESOURCE_NOT_AVAILABLE_OR_OPERATOR_INTERVENTION: Self = _
DB2-specific: Class 57
: Resource not available or operator intervention
sourcepub const DB2_SYSTEM_ERROR: Self = _
pub const DB2_SYSTEM_ERROR: Self = _
DB2-specific: Class 58
: System error
sourcepub const DB2_COMMON_UTILITIES_AND_TOOLS: Self = _
pub const DB2_COMMON_UTILITIES_AND_TOOLS: Self = _
DB2-specific: Class 5U
: Common utilities and tools
source§impl Class
impl Class
sourcepub const PGSQL_INSUFFICIENT_RESOURCES: Self = _
pub const PGSQL_INSUFFICIENT_RESOURCES: Self = _
Postgres-specific: Class 53
: Invalid operand or inconsistent specification
sourcepub const PGSQL_PROGRAM_LIMIT_EXCEEDED: Self = _
pub const PGSQL_PROGRAM_LIMIT_EXCEEDED: Self = _
Postgres-specific: Class 54
: Program limit exceeded
sourcepub const PGSQL_OBJECT_NOT_IN_PREREQUISITE_STATE: Self = _
pub const PGSQL_OBJECT_NOT_IN_PREREQUISITE_STATE: Self = _
Postgres-specific: Class 55
: Object not in prerequisite state
sourcepub const PGSQL_OPERATOR_INTERVENTION: Self = _
pub const PGSQL_OPERATOR_INTERVENTION: Self = _
Postgres-specific: Class 57
: Operator intervention
sourcepub const PGSQL_SYSTEM_ERROR: Self = _
pub const PGSQL_SYSTEM_ERROR: Self = _
Postgres-specific: Class 58
: System error (errors external to PostgreSQL itself)
sourcepub const PGSQL_SNAPSHOT_FAILURE: Self = _
pub const PGSQL_SNAPSHOT_FAILURE: Self = _
Postgres-specific: Class 72
: Snapshot Failure
sourcepub const PGSQL_CONFIGURATION_FILE_ERROR: Self = _
pub const PGSQL_CONFIGURATION_FILE_ERROR: Self = _
Postgres-specific: Class F0
: Configuration File Error
sourcepub const PGSQL_PL_PGSQL_ERROR: Self = _
pub const PGSQL_PL_PGSQL_ERROR: Self = _
Postgres-specific: Class P0
: PL/pgSQL error
sourcepub const PGSQL_INTERNAL_ERROR: Self = _
pub const PGSQL_INTERNAL_ERROR: Self = _
Postgres-specific: Class XX
: Internal error
source§impl Class
impl Class
sourcepub const MYSQL_INTERRUPTION: Self = _
pub const MYSQL_INTERRUPTION: Self = _
MySQL-specific: Class 70
: Interruption
sourcepub const MYSQL_XA_ERROR: Self = _
pub const MYSQL_XA_ERROR: Self = _
MySQL-specific: Class XA
: X/Open XA related error
source§impl Class
impl Class
sourcepub const ODBC_DRIVER_ERROR: Self = _
pub const ODBC_DRIVER_ERROR: Self = _
ODBC-specific: Class IM
: Driver error
source§impl Class
impl Class
sourcepub const ORACLE_SYSTEM_ERROR: Self = _
pub const ORACLE_SYSTEM_ERROR: Self = _
Oracle-specific: Class 60
: System error
sourcepub const ORACLE_RESOURCE_ERROR: Self = _
pub const ORACLE_RESOURCE_ERROR: Self = _
Oracle-specific: Class 61
: Resource error
sourcepub const ORACLE_PATH_NAME_SERVER_AND_DETACHED_PROCESS_ERROR: Self = _
pub const ORACLE_PATH_NAME_SERVER_AND_DETACHED_PROCESS_ERROR: Self = _
Oracle-specific: Class 62
: Path name server and detached process error
sourcepub const ORACLE_CA_OR_TWO_TASK_INTERFACE_ERROR: Self = _
pub const ORACLE_CA_OR_TWO_TASK_INTERFACE_ERROR: Self = _
Oracle-specific: Class 63
: Oracle*XA or two-task interface error
sourcepub const ORACLE_FILE_OR_MEDIA_RECOVERY_ERROR: Self = _
pub const ORACLE_FILE_OR_MEDIA_RECOVERY_ERROR: Self = _
Oracle-specific: Class 64
: control file, database file, redo file, archival or media recovery error
sourcepub const ORACLE_PL_SQL_ERROR: Self = _
pub const ORACLE_PL_SQL_ERROR: Self = _
Oracle-specific: Class 65
: PL/SQL error
sourcepub const ORACLE_SQL_NET_DRIVER_ERROR: Self = _
pub const ORACLE_SQL_NET_DRIVER_ERROR: Self = _
Oracle-specific: Class 66
: SQL*Net driver error
sourcepub const ORACLE_LICENSING_ERROR: Self = _
pub const ORACLE_LICENSING_ERROR: Self = _
Oracle-specific: Class 67
: Licensing error
sourcepub const ORACLE_SQL_CONNECT_ERROR: Self = _
pub const ORACLE_SQL_CONNECT_ERROR: Self = _
Oracle-specific: Class 69
: SQL*Connect error
sourcepub const ORACLE_SQL_EXECUTE_PHASE_ERROR: Self = _
pub const ORACLE_SQL_EXECUTE_PHASE_ERROR: Self = _
Oracle-specific: Class 72
: SQL execute phase error
sourcepub const ORACLE_INTERNAL_ERROR: Self = _
pub const ORACLE_INTERNAL_ERROR: Self = _
Oracle-specific: Class 82
: Internal error
sourcepub const ORACLE_DEBUG_EVENT: Self = _
pub const ORACLE_DEBUG_EVENT: Self = _
Oracle-specific: Class 90
: Debug event
Methods from Deref<Target = str>§
1.0.0 · sourcepub fn len(&self) -> usize
pub fn len(&self) -> usize
Returns the length of self
.
This length is in bytes, not char
s or graphemes. In other words,
it might not be what a human considers the length of the string.
Examples
Basic usage:
let len = "foo".len();
assert_eq!(3, len);
assert_eq!("ƒoo".len(), 4); // fancy f!
assert_eq!("ƒoo".chars().count(), 3);
1.0.0 · sourcepub fn is_empty(&self) -> bool
pub fn is_empty(&self) -> bool
Returns true
if self
has a length of zero bytes.
Examples
Basic usage:
let s = "";
assert!(s.is_empty());
let s = "not empty";
assert!(!s.is_empty());
1.9.0 · sourcepub fn is_char_boundary(&self, index: usize) -> bool
pub fn is_char_boundary(&self, index: usize) -> bool
Checks that index
-th byte is the first byte in a UTF-8 code point
sequence or the end of the string.
The start and end of the string (when index == self.len()
) are
considered to be boundaries.
Returns false
if index
is greater than self.len()
.
Examples
let s = "Löwe 老虎 Léopard";
assert!(s.is_char_boundary(0));
// start of `老`
assert!(s.is_char_boundary(6));
assert!(s.is_char_boundary(s.len()));
// second byte of `ö`
assert!(!s.is_char_boundary(2));
// third byte of `老`
assert!(!s.is_char_boundary(8));
sourcepub fn floor_char_boundary(&self, index: usize) -> usize
🔬This is a nightly-only experimental API. (round_char_boundary
)
pub fn floor_char_boundary(&self, index: usize) -> usize
round_char_boundary
)Finds the closest x
not exceeding index
where is_char_boundary(x)
is true
.
This method can help you truncate a string so that it’s still valid UTF-8, but doesn’t exceed a given number of bytes. Note that this is done purely at the character level and can still visually split graphemes, even though the underlying characters aren’t split. For example, the emoji 🧑🔬 (scientist) could be split so that the string only includes 🧑 (person) instead.
Examples
#![feature(round_char_boundary)]
let s = "❤️🧡💛💚💙💜";
assert_eq!(s.len(), 26);
assert!(!s.is_char_boundary(13));
let closest = s.floor_char_boundary(13);
assert_eq!(closest, 10);
assert_eq!(&s[..closest], "❤️🧡");
sourcepub fn ceil_char_boundary(&self, index: usize) -> usize
🔬This is a nightly-only experimental API. (round_char_boundary
)
pub fn ceil_char_boundary(&self, index: usize) -> usize
round_char_boundary
)Finds the closest x
not below index
where is_char_boundary(x)
is true
.
This method is the natural complement to floor_char_boundary
. See that method
for more details.
Panics
Panics if index > self.len()
.
Examples
#![feature(round_char_boundary)]
let s = "❤️🧡💛💚💙💜";
assert_eq!(s.len(), 26);
assert!(!s.is_char_boundary(13));
let closest = s.ceil_char_boundary(13);
assert_eq!(closest, 14);
assert_eq!(&s[..closest], "❤️🧡💛");
1.0.0 · sourcepub fn as_ptr(&self) -> *const u8
pub fn as_ptr(&self) -> *const u8
Converts a string slice to a raw pointer.
As string slices are a slice of bytes, the raw pointer points to a
u8
. This pointer will be pointing to the first byte of the string
slice.
The caller must ensure that the returned pointer is never written to.
If you need to mutate the contents of the string slice, use as_mut_ptr
.
Examples
Basic usage:
let s = "Hello";
let ptr = s.as_ptr();
1.20.0 · sourcepub fn get<I>(&self, i: I) -> Option<&<I as SliceIndex<str>>::Output>where
I: SliceIndex<str>,
pub fn get<I>(&self, i: I) -> Option<&<I as SliceIndex<str>>::Output>where
I: SliceIndex<str>,
Returns a subslice of str
.
This is the non-panicking alternative to indexing the str
. Returns
None
whenever equivalent indexing operation would panic.
Examples
let v = String::from("🗻∈🌏");
assert_eq!(Some("🗻"), v.get(0..4));
// indices not on UTF-8 sequence boundaries
assert!(v.get(1..).is_none());
assert!(v.get(..8).is_none());
// out of bounds
assert!(v.get(..42).is_none());
1.20.0 · sourcepub unsafe fn get_unchecked<I>(&self, i: I) -> &<I as SliceIndex<str>>::Outputwhere
I: SliceIndex<str>,
pub unsafe fn get_unchecked<I>(&self, i: I) -> &<I as SliceIndex<str>>::Outputwhere
I: SliceIndex<str>,
Returns an unchecked subslice of str
.
This is the unchecked alternative to indexing the str
.
Safety
Callers of this function are responsible that these preconditions are satisfied:
- The starting index must not exceed the ending index;
- Indexes must be within bounds of the original slice;
- Indexes must lie on UTF-8 sequence boundaries.
Failing that, the returned string slice may reference invalid memory or
violate the invariants communicated by the str
type.
Examples
let v = "🗻∈🌏";
unsafe {
assert_eq!("🗻", v.get_unchecked(0..4));
assert_eq!("∈", v.get_unchecked(4..7));
assert_eq!("🌏", v.get_unchecked(7..11));
}
1.0.0 · sourcepub unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str
👎Deprecated since 1.29.0: use get_unchecked(begin..end)
instead
pub unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str
get_unchecked(begin..end)
insteadCreates a string slice from another string slice, bypassing safety checks.
This is generally not recommended, use with caution! For a safe
alternative see str
and Index
.
This new slice goes from begin
to end
, including begin
but
excluding end
.
To get a mutable string slice instead, see the
slice_mut_unchecked
method.
Safety
Callers of this function are responsible that three preconditions are satisfied:
begin
must not exceedend
.begin
andend
must be byte positions within the string slice.begin
andend
must lie on UTF-8 sequence boundaries.
Examples
Basic usage:
let s = "Löwe 老虎 Léopard";
unsafe {
assert_eq!("Löwe 老虎 Léopard", s.slice_unchecked(0, 21));
}
let s = "Hello, world!";
unsafe {
assert_eq!("world", s.slice_unchecked(7, 12));
}
1.4.0 · sourcepub fn split_at(&self, mid: usize) -> (&str, &str)
pub fn split_at(&self, mid: usize) -> (&str, &str)
Divide one string slice into two at an index.
The argument, mid
, should be a byte offset from the start of the
string. It must also be on the boundary of a UTF-8 code point.
The two slices returned go from the start of the string slice to mid
,
and from mid
to the end of the string slice.
To get mutable string slices instead, see the split_at_mut
method.
Panics
Panics if mid
is not on a UTF-8 code point boundary, or if it is
past the end of the last code point of the string slice.
Examples
Basic usage:
let s = "Per Martin-Löf";
let (first, last) = s.split_at(3);
assert_eq!("Per", first);
assert_eq!(" Martin-Löf", last);
1.0.0 · sourcepub fn chars(&self) -> Chars<'_>
pub fn chars(&self) -> Chars<'_>
Returns an iterator over the char
s of a string slice.
As a string slice consists of valid UTF-8, we can iterate through a
string slice by char
. This method returns such an iterator.
It’s important to remember that char
represents a Unicode Scalar
Value, and might not match your idea of what a ‘character’ is. Iteration
over grapheme clusters may be what you actually want. This functionality
is not provided by Rust’s standard library, check crates.io instead.
Examples
Basic usage:
let word = "goodbye";
let count = word.chars().count();
assert_eq!(7, count);
let mut chars = word.chars();
assert_eq!(Some('g'), chars.next());
assert_eq!(Some('o'), chars.next());
assert_eq!(Some('o'), chars.next());
assert_eq!(Some('d'), chars.next());
assert_eq!(Some('b'), chars.next());
assert_eq!(Some('y'), chars.next());
assert_eq!(Some('e'), chars.next());
assert_eq!(None, chars.next());
Remember, char
s might not match your intuition about characters:
let y = "y̆";
let mut chars = y.chars();
assert_eq!(Some('y'), chars.next()); // not 'y̆'
assert_eq!(Some('\u{0306}'), chars.next());
assert_eq!(None, chars.next());
1.0.0 · sourcepub fn char_indices(&self) -> CharIndices<'_>
pub fn char_indices(&self) -> CharIndices<'_>
Returns an iterator over the char
s of a string slice, and their
positions.
As a string slice consists of valid UTF-8, we can iterate through a
string slice by char
. This method returns an iterator of both
these char
s, as well as their byte positions.
The iterator yields tuples. The position is first, the char
is
second.
Examples
Basic usage:
let word = "goodbye";
let count = word.char_indices().count();
assert_eq!(7, count);
let mut char_indices = word.char_indices();
assert_eq!(Some((0, 'g')), char_indices.next());
assert_eq!(Some((1, 'o')), char_indices.next());
assert_eq!(Some((2, 'o')), char_indices.next());
assert_eq!(Some((3, 'd')), char_indices.next());
assert_eq!(Some((4, 'b')), char_indices.next());
assert_eq!(Some((5, 'y')), char_indices.next());
assert_eq!(Some((6, 'e')), char_indices.next());
assert_eq!(None, char_indices.next());
Remember, char
s might not match your intuition about characters:
let yes = "y̆es";
let mut char_indices = yes.char_indices();
assert_eq!(Some((0, 'y')), char_indices.next()); // not (0, 'y̆')
assert_eq!(Some((1, '\u{0306}')), char_indices.next());
// note the 3 here - the last character took up two bytes
assert_eq!(Some((3, 'e')), char_indices.next());
assert_eq!(Some((4, 's')), char_indices.next());
assert_eq!(None, char_indices.next());
1.0.0 · sourcepub fn bytes(&self) -> Bytes<'_>
pub fn bytes(&self) -> Bytes<'_>
An iterator over the bytes of a string slice.
As a string slice consists of a sequence of bytes, we can iterate through a string slice by byte. This method returns such an iterator.
Examples
Basic usage:
let mut bytes = "bors".bytes();
assert_eq!(Some(b'b'), bytes.next());
assert_eq!(Some(b'o'), bytes.next());
assert_eq!(Some(b'r'), bytes.next());
assert_eq!(Some(b's'), bytes.next());
assert_eq!(None, bytes.next());
1.1.0 · sourcepub fn split_whitespace(&self) -> SplitWhitespace<'_>
pub fn split_whitespace(&self) -> SplitWhitespace<'_>
Splits a string slice by whitespace.
The iterator returned will return string slices that are sub-slices of the original string slice, separated by any amount of whitespace.
‘Whitespace’ is defined according to the terms of the Unicode Derived
Core Property White_Space
. If you only want to split on ASCII whitespace
instead, use split_ascii_whitespace
.
Examples
Basic usage:
let mut iter = "A few words".split_whitespace();
assert_eq!(Some("A"), iter.next());
assert_eq!(Some("few"), iter.next());
assert_eq!(Some("words"), iter.next());
assert_eq!(None, iter.next());
All kinds of whitespace are considered:
let mut iter = " Mary had\ta\u{2009}little \n\t lamb".split_whitespace();
assert_eq!(Some("Mary"), iter.next());
assert_eq!(Some("had"), iter.next());
assert_eq!(Some("a"), iter.next());
assert_eq!(Some("little"), iter.next());
assert_eq!(Some("lamb"), iter.next());
assert_eq!(None, iter.next());
If the string is empty or all whitespace, the iterator yields no string slices:
assert_eq!("".split_whitespace().next(), None);
assert_eq!(" ".split_whitespace().next(), None);
1.34.0 · sourcepub fn split_ascii_whitespace(&self) -> SplitAsciiWhitespace<'_>
pub fn split_ascii_whitespace(&self) -> SplitAsciiWhitespace<'_>
Splits a string slice by ASCII whitespace.
The iterator returned will return string slices that are sub-slices of the original string slice, separated by any amount of ASCII whitespace.
To split by Unicode Whitespace
instead, use split_whitespace
.
Examples
Basic usage:
let mut iter = "A few words".split_ascii_whitespace();
assert_eq!(Some("A"), iter.next());
assert_eq!(Some("few"), iter.next());
assert_eq!(Some("words"), iter.next());
assert_eq!(None, iter.next());
All kinds of ASCII whitespace are considered:
let mut iter = " Mary had\ta little \n\t lamb".split_ascii_whitespace();
assert_eq!(Some("Mary"), iter.next());
assert_eq!(Some("had"), iter.next());
assert_eq!(Some("a"), iter.next());
assert_eq!(Some("little"), iter.next());
assert_eq!(Some("lamb"), iter.next());
assert_eq!(None, iter.next());
If the string is empty or all ASCII whitespace, the iterator yields no string slices:
assert_eq!("".split_ascii_whitespace().next(), None);
assert_eq!(" ".split_ascii_whitespace().next(), None);
1.0.0 · sourcepub fn lines(&self) -> Lines<'_>
pub fn lines(&self) -> Lines<'_>
An iterator over the lines of a string, as string slices.
Lines are ended with either a newline (\n
) or a carriage return with
a line feed (\r\n
).
The final line ending is optional. A string that ends with a final line ending will return the same lines as an otherwise identical string without a final line ending.
Examples
Basic usage:
let text = "foo\r\nbar\n\nbaz\n";
let mut lines = text.lines();
assert_eq!(Some("foo"), lines.next());
assert_eq!(Some("bar"), lines.next());
assert_eq!(Some(""), lines.next());
assert_eq!(Some("baz"), lines.next());
assert_eq!(None, lines.next());
The final line ending isn’t required:
let text = "foo\nbar\n\r\nbaz";
let mut lines = text.lines();
assert_eq!(Some("foo"), lines.next());
assert_eq!(Some("bar"), lines.next());
assert_eq!(Some(""), lines.next());
assert_eq!(Some("baz"), lines.next());
assert_eq!(None, lines.next());
1.0.0 · sourcepub fn lines_any(&self) -> LinesAny<'_>
👎Deprecated since 1.4.0: use lines() instead now
pub fn lines_any(&self) -> LinesAny<'_>
An iterator over the lines of a string.
1.8.0 · sourcepub fn encode_utf16(&self) -> EncodeUtf16<'_>
pub fn encode_utf16(&self) -> EncodeUtf16<'_>
Returns an iterator of u16
over the string encoded as UTF-16.
Examples
Basic usage:
let text = "Zażółć gęślą jaźń";
let utf8_len = text.len();
let utf16_len = text.encode_utf16().count();
assert!(utf16_len <= utf8_len);
1.0.0 · sourcepub fn contains<'a, P>(&'a self, pat: P) -> boolwhere
P: Pattern<'a>,
pub fn contains<'a, P>(&'a self, pat: P) -> boolwhere
P: Pattern<'a>,
Returns true
if the given pattern matches a sub-slice of
this string slice.
Returns false
if it does not.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Examples
Basic usage:
let bananas = "bananas";
assert!(bananas.contains("nana"));
assert!(!bananas.contains("apples"));
1.0.0 · sourcepub fn starts_with<'a, P>(&'a self, pat: P) -> boolwhere
P: Pattern<'a>,
pub fn starts_with<'a, P>(&'a self, pat: P) -> boolwhere
P: Pattern<'a>,
Returns true
if the given pattern matches a prefix of this
string slice.
Returns false
if it does not.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Examples
Basic usage:
let bananas = "bananas";
assert!(bananas.starts_with("bana"));
assert!(!bananas.starts_with("nana"));
1.0.0 · sourcepub fn ends_with<'a, P>(&'a self, pat: P) -> boolwhere
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn ends_with<'a, P>(&'a self, pat: P) -> boolwhere
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
Returns true
if the given pattern matches a suffix of this
string slice.
Returns false
if it does not.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Examples
Basic usage:
let bananas = "bananas";
assert!(bananas.ends_with("anas"));
assert!(!bananas.ends_with("nana"));
1.0.0 · sourcepub fn find<'a, P>(&'a self, pat: P) -> Option<usize>where
P: Pattern<'a>,
pub fn find<'a, P>(&'a self, pat: P) -> Option<usize>where
P: Pattern<'a>,
Returns the byte index of the first character of this string slice that matches the pattern.
Returns None
if the pattern doesn’t match.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Examples
Simple patterns:
let s = "Löwe 老虎 Léopard Gepardi";
assert_eq!(s.find('L'), Some(0));
assert_eq!(s.find('é'), Some(14));
assert_eq!(s.find("pard"), Some(17));
More complex patterns using point-free style and closures:
let s = "Löwe 老虎 Léopard";
assert_eq!(s.find(char::is_whitespace), Some(5));
assert_eq!(s.find(char::is_lowercase), Some(1));
assert_eq!(s.find(|c: char| c.is_whitespace() || c.is_lowercase()), Some(1));
assert_eq!(s.find(|c: char| (c < 'o') && (c > 'a')), Some(4));
Not finding the pattern:
let s = "Löwe 老虎 Léopard";
let x: &[_] = &['1', '2'];
assert_eq!(s.find(x), None);
1.0.0 · sourcepub fn rfind<'a, P>(&'a self, pat: P) -> Option<usize>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn rfind<'a, P>(&'a self, pat: P) -> Option<usize>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
Returns the byte index for the first character of the last match of the pattern in this string slice.
Returns None
if the pattern doesn’t match.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Examples
Simple patterns:
let s = "Löwe 老虎 Léopard Gepardi";
assert_eq!(s.rfind('L'), Some(13));
assert_eq!(s.rfind('é'), Some(14));
assert_eq!(s.rfind("pard"), Some(24));
More complex patterns with closures:
let s = "Löwe 老虎 Léopard";
assert_eq!(s.rfind(char::is_whitespace), Some(12));
assert_eq!(s.rfind(char::is_lowercase), Some(20));
Not finding the pattern:
let s = "Löwe 老虎 Léopard";
let x: &[_] = &['1', '2'];
assert_eq!(s.rfind(x), None);
1.0.0 · sourcepub fn split<'a, P>(&'a self, pat: P) -> Split<'a, P>where
P: Pattern<'a>,
pub fn split<'a, P>(&'a self, pat: P) -> Split<'a, P>where
P: Pattern<'a>,
An iterator over substrings of this string slice, separated by characters matched by a pattern.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Iterator behavior
The returned iterator will be a DoubleEndedIterator
if the pattern
allows a reverse search and forward/reverse search yields the same
elements. This is true for, e.g., char
, but not for &str
.
If the pattern allows a reverse search but its results might differ
from a forward search, the rsplit
method can be used.
Examples
Simple patterns:
let v: Vec<&str> = "Mary had a little lamb".split(' ').collect();
assert_eq!(v, ["Mary", "had", "a", "little", "lamb"]);
let v: Vec<&str> = "".split('X').collect();
assert_eq!(v, [""]);
let v: Vec<&str> = "lionXXtigerXleopard".split('X').collect();
assert_eq!(v, ["lion", "", "tiger", "leopard"]);
let v: Vec<&str> = "lion::tiger::leopard".split("::").collect();
assert_eq!(v, ["lion", "tiger", "leopard"]);
let v: Vec<&str> = "abc1def2ghi".split(char::is_numeric).collect();
assert_eq!(v, ["abc", "def", "ghi"]);
let v: Vec<&str> = "lionXtigerXleopard".split(char::is_uppercase).collect();
assert_eq!(v, ["lion", "tiger", "leopard"]);
If the pattern is a slice of chars, split on each occurrence of any of the characters:
let v: Vec<&str> = "2020-11-03 23:59".split(&['-', ' ', ':', '@'][..]).collect();
assert_eq!(v, ["2020", "11", "03", "23", "59"]);
A more complex pattern, using a closure:
let v: Vec<&str> = "abc1defXghi".split(|c| c == '1' || c == 'X').collect();
assert_eq!(v, ["abc", "def", "ghi"]);
If a string contains multiple contiguous separators, you will end up with empty strings in the output:
let x = "||||a||b|c".to_string();
let d: Vec<_> = x.split('|').collect();
assert_eq!(d, &["", "", "", "", "a", "", "b", "c"]);
Contiguous separators are separated by the empty string.
let x = "(///)".to_string();
let d: Vec<_> = x.split('/').collect();
assert_eq!(d, &["(", "", "", ")"]);
Separators at the start or end of a string are neighbored by empty strings.
let d: Vec<_> = "010".split("0").collect();
assert_eq!(d, &["", "1", ""]);
When the empty string is used as a separator, it separates every character in the string, along with the beginning and end of the string.
let f: Vec<_> = "rust".split("").collect();
assert_eq!(f, &["", "r", "u", "s", "t", ""]);
Contiguous separators can lead to possibly surprising behavior when whitespace is used as the separator. This code is correct:
let x = " a b c".to_string();
let d: Vec<_> = x.split(' ').collect();
assert_eq!(d, &["", "", "", "", "a", "", "b", "c"]);
It does not give you:
assert_eq!(d, &["a", "b", "c"]);
Use split_whitespace
for this behavior.
1.51.0 · sourcepub fn split_inclusive<'a, P>(&'a self, pat: P) -> SplitInclusive<'a, P>where
P: Pattern<'a>,
pub fn split_inclusive<'a, P>(&'a self, pat: P) -> SplitInclusive<'a, P>where
P: Pattern<'a>,
An iterator over substrings of this string slice, separated by
characters matched by a pattern. Differs from the iterator produced by
split
in that split_inclusive
leaves the matched part as the
terminator of the substring.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Examples
let v: Vec<&str> = "Mary had a little lamb\nlittle lamb\nlittle lamb."
.split_inclusive('\n').collect();
assert_eq!(v, ["Mary had a little lamb\n", "little lamb\n", "little lamb."]);
If the last element of the string is matched, that element will be considered the terminator of the preceding substring. That substring will be the last item returned by the iterator.
let v: Vec<&str> = "Mary had a little lamb\nlittle lamb\nlittle lamb.\n"
.split_inclusive('\n').collect();
assert_eq!(v, ["Mary had a little lamb\n", "little lamb\n", "little lamb.\n"]);
1.0.0 · sourcepub fn rsplit<'a, P>(&'a self, pat: P) -> RSplit<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn rsplit<'a, P>(&'a self, pat: P) -> RSplit<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
An iterator over substrings of the given string slice, separated by characters matched by a pattern and yielded in reverse order.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Iterator behavior
The returned iterator requires that the pattern supports a reverse
search, and it will be a DoubleEndedIterator
if a forward/reverse
search yields the same elements.
For iterating from the front, the split
method can be used.
Examples
Simple patterns:
let v: Vec<&str> = "Mary had a little lamb".rsplit(' ').collect();
assert_eq!(v, ["lamb", "little", "a", "had", "Mary"]);
let v: Vec<&str> = "".rsplit('X').collect();
assert_eq!(v, [""]);
let v: Vec<&str> = "lionXXtigerXleopard".rsplit('X').collect();
assert_eq!(v, ["leopard", "tiger", "", "lion"]);
let v: Vec<&str> = "lion::tiger::leopard".rsplit("::").collect();
assert_eq!(v, ["leopard", "tiger", "lion"]);
A more complex pattern, using a closure:
let v: Vec<&str> = "abc1defXghi".rsplit(|c| c == '1' || c == 'X').collect();
assert_eq!(v, ["ghi", "def", "abc"]);
1.0.0 · sourcepub fn split_terminator<'a, P>(&'a self, pat: P) -> SplitTerminator<'a, P>where
P: Pattern<'a>,
pub fn split_terminator<'a, P>(&'a self, pat: P) -> SplitTerminator<'a, P>where
P: Pattern<'a>,
An iterator over substrings of the given string slice, separated by characters matched by a pattern.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Equivalent to split
, except that the trailing substring
is skipped if empty.
This method can be used for string data that is terminated, rather than separated by a pattern.
Iterator behavior
The returned iterator will be a DoubleEndedIterator
if the pattern
allows a reverse search and forward/reverse search yields the same
elements. This is true for, e.g., char
, but not for &str
.
If the pattern allows a reverse search but its results might differ
from a forward search, the rsplit_terminator
method can be used.
Examples
Basic usage:
let v: Vec<&str> = "A.B.".split_terminator('.').collect();
assert_eq!(v, ["A", "B"]);
let v: Vec<&str> = "A..B..".split_terminator(".").collect();
assert_eq!(v, ["A", "", "B", ""]);
let v: Vec<&str> = "A.B:C.D".split_terminator(&['.', ':'][..]).collect();
assert_eq!(v, ["A", "B", "C", "D"]);
1.0.0 · sourcepub fn rsplit_terminator<'a, P>(&'a self, pat: P) -> RSplitTerminator<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn rsplit_terminator<'a, P>(&'a self, pat: P) -> RSplitTerminator<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
An iterator over substrings of self
, separated by characters
matched by a pattern and yielded in reverse order.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Equivalent to split
, except that the trailing substring is
skipped if empty.
This method can be used for string data that is terminated, rather than separated by a pattern.
Iterator behavior
The returned iterator requires that the pattern supports a reverse search, and it will be double ended if a forward/reverse search yields the same elements.
For iterating from the front, the split_terminator
method can be
used.
Examples
let v: Vec<&str> = "A.B.".rsplit_terminator('.').collect();
assert_eq!(v, ["B", "A"]);
let v: Vec<&str> = "A..B..".rsplit_terminator(".").collect();
assert_eq!(v, ["", "B", "", "A"]);
let v: Vec<&str> = "A.B:C.D".rsplit_terminator(&['.', ':'][..]).collect();
assert_eq!(v, ["D", "C", "B", "A"]);
1.0.0 · sourcepub fn splitn<'a, P>(&'a self, n: usize, pat: P) -> SplitN<'a, P>where
P: Pattern<'a>,
pub fn splitn<'a, P>(&'a self, n: usize, pat: P) -> SplitN<'a, P>where
P: Pattern<'a>,
An iterator over substrings of the given string slice, separated by a
pattern, restricted to returning at most n
items.
If n
substrings are returned, the last substring (the n
th substring)
will contain the remainder of the string.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Iterator behavior
The returned iterator will not be double ended, because it is not efficient to support.
If the pattern allows a reverse search, the rsplitn
method can be
used.
Examples
Simple patterns:
let v: Vec<&str> = "Mary had a little lambda".splitn(3, ' ').collect();
assert_eq!(v, ["Mary", "had", "a little lambda"]);
let v: Vec<&str> = "lionXXtigerXleopard".splitn(3, "X").collect();
assert_eq!(v, ["lion", "", "tigerXleopard"]);
let v: Vec<&str> = "abcXdef".splitn(1, 'X').collect();
assert_eq!(v, ["abcXdef"]);
let v: Vec<&str> = "".splitn(1, 'X').collect();
assert_eq!(v, [""]);
A more complex pattern, using a closure:
let v: Vec<&str> = "abc1defXghi".splitn(2, |c| c == '1' || c == 'X').collect();
assert_eq!(v, ["abc", "defXghi"]);
1.0.0 · sourcepub fn rsplitn<'a, P>(&'a self, n: usize, pat: P) -> RSplitN<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn rsplitn<'a, P>(&'a self, n: usize, pat: P) -> RSplitN<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
An iterator over substrings of this string slice, separated by a
pattern, starting from the end of the string, restricted to returning
at most n
items.
If n
substrings are returned, the last substring (the n
th substring)
will contain the remainder of the string.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Iterator behavior
The returned iterator will not be double ended, because it is not efficient to support.
For splitting from the front, the splitn
method can be used.
Examples
Simple patterns:
let v: Vec<&str> = "Mary had a little lamb".rsplitn(3, ' ').collect();
assert_eq!(v, ["lamb", "little", "Mary had a"]);
let v: Vec<&str> = "lionXXtigerXleopard".rsplitn(3, 'X').collect();
assert_eq!(v, ["leopard", "tiger", "lionX"]);
let v: Vec<&str> = "lion::tiger::leopard".rsplitn(2, "::").collect();
assert_eq!(v, ["leopard", "lion::tiger"]);
A more complex pattern, using a closure:
let v: Vec<&str> = "abc1defXghi".rsplitn(2, |c| c == '1' || c == 'X').collect();
assert_eq!(v, ["ghi", "abc1def"]);
1.52.0 · sourcepub fn split_once<'a, P>(&'a self, delimiter: P) -> Option<(&'a str, &'a str)>where
P: Pattern<'a>,
pub fn split_once<'a, P>(&'a self, delimiter: P) -> Option<(&'a str, &'a str)>where
P: Pattern<'a>,
Splits the string on the first occurrence of the specified delimiter and returns prefix before delimiter and suffix after delimiter.
Examples
assert_eq!("cfg".split_once('='), None);
assert_eq!("cfg=".split_once('='), Some(("cfg", "")));
assert_eq!("cfg=foo".split_once('='), Some(("cfg", "foo")));
assert_eq!("cfg=foo=bar".split_once('='), Some(("cfg", "foo=bar")));
1.52.0 · sourcepub fn rsplit_once<'a, P>(&'a self, delimiter: P) -> Option<(&'a str, &'a str)>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn rsplit_once<'a, P>(&'a self, delimiter: P) -> Option<(&'a str, &'a str)>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
Splits the string on the last occurrence of the specified delimiter and returns prefix before delimiter and suffix after delimiter.
Examples
assert_eq!("cfg".rsplit_once('='), None);
assert_eq!("cfg=foo".rsplit_once('='), Some(("cfg", "foo")));
assert_eq!("cfg=foo=bar".rsplit_once('='), Some(("cfg=foo", "bar")));
1.2.0 · sourcepub fn matches<'a, P>(&'a self, pat: P) -> Matches<'a, P>where
P: Pattern<'a>,
pub fn matches<'a, P>(&'a self, pat: P) -> Matches<'a, P>where
P: Pattern<'a>,
An iterator over the disjoint matches of a pattern within the given string slice.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Iterator behavior
The returned iterator will be a DoubleEndedIterator
if the pattern
allows a reverse search and forward/reverse search yields the same
elements. This is true for, e.g., char
, but not for &str
.
If the pattern allows a reverse search but its results might differ
from a forward search, the rmatches
method can be used.
Examples
Basic usage:
let v: Vec<&str> = "abcXXXabcYYYabc".matches("abc").collect();
assert_eq!(v, ["abc", "abc", "abc"]);
let v: Vec<&str> = "1abc2abc3".matches(char::is_numeric).collect();
assert_eq!(v, ["1", "2", "3"]);
1.2.0 · sourcepub fn rmatches<'a, P>(&'a self, pat: P) -> RMatches<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn rmatches<'a, P>(&'a self, pat: P) -> RMatches<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
An iterator over the disjoint matches of a pattern within this string slice, yielded in reverse order.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Iterator behavior
The returned iterator requires that the pattern supports a reverse
search, and it will be a DoubleEndedIterator
if a forward/reverse
search yields the same elements.
For iterating from the front, the matches
method can be used.
Examples
Basic usage:
let v: Vec<&str> = "abcXXXabcYYYabc".rmatches("abc").collect();
assert_eq!(v, ["abc", "abc", "abc"]);
let v: Vec<&str> = "1abc2abc3".rmatches(char::is_numeric).collect();
assert_eq!(v, ["3", "2", "1"]);
1.5.0 · sourcepub fn match_indices<'a, P>(&'a self, pat: P) -> MatchIndices<'a, P>where
P: Pattern<'a>,
pub fn match_indices<'a, P>(&'a self, pat: P) -> MatchIndices<'a, P>where
P: Pattern<'a>,
An iterator over the disjoint matches of a pattern within this string slice as well as the index that the match starts at.
For matches of pat
within self
that overlap, only the indices
corresponding to the first match are returned.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Iterator behavior
The returned iterator will be a DoubleEndedIterator
if the pattern
allows a reverse search and forward/reverse search yields the same
elements. This is true for, e.g., char
, but not for &str
.
If the pattern allows a reverse search but its results might differ
from a forward search, the rmatch_indices
method can be used.
Examples
Basic usage:
let v: Vec<_> = "abcXXXabcYYYabc".match_indices("abc").collect();
assert_eq!(v, [(0, "abc"), (6, "abc"), (12, "abc")]);
let v: Vec<_> = "1abcabc2".match_indices("abc").collect();
assert_eq!(v, [(1, "abc"), (4, "abc")]);
let v: Vec<_> = "ababa".match_indices("aba").collect();
assert_eq!(v, [(0, "aba")]); // only the first `aba`
1.5.0 · sourcepub fn rmatch_indices<'a, P>(&'a self, pat: P) -> RMatchIndices<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn rmatch_indices<'a, P>(&'a self, pat: P) -> RMatchIndices<'a, P>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
An iterator over the disjoint matches of a pattern within self
,
yielded in reverse order along with the index of the match.
For matches of pat
within self
that overlap, only the indices
corresponding to the last match are returned.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Iterator behavior
The returned iterator requires that the pattern supports a reverse
search, and it will be a DoubleEndedIterator
if a forward/reverse
search yields the same elements.
For iterating from the front, the match_indices
method can be used.
Examples
Basic usage:
let v: Vec<_> = "abcXXXabcYYYabc".rmatch_indices("abc").collect();
assert_eq!(v, [(12, "abc"), (6, "abc"), (0, "abc")]);
let v: Vec<_> = "1abcabc2".rmatch_indices("abc").collect();
assert_eq!(v, [(4, "abc"), (1, "abc")]);
let v: Vec<_> = "ababa".rmatch_indices("aba").collect();
assert_eq!(v, [(2, "aba")]); // only the last `aba`
1.0.0 · sourcepub fn trim(&self) -> &str
pub fn trim(&self) -> &str
Returns a string slice with leading and trailing whitespace removed.
‘Whitespace’ is defined according to the terms of the Unicode Derived
Core Property White_Space
, which includes newlines.
Examples
Basic usage:
let s = "\n Hello\tworld\t\n";
assert_eq!("Hello\tworld", s.trim());
1.30.0 · sourcepub fn trim_start(&self) -> &str
pub fn trim_start(&self) -> &str
Returns a string slice with leading whitespace removed.
‘Whitespace’ is defined according to the terms of the Unicode Derived
Core Property White_Space
, which includes newlines.
Text directionality
A string is a sequence of bytes. start
in this context means the first
position of that byte string; for a left-to-right language like English or
Russian, this will be left side, and for right-to-left languages like
Arabic or Hebrew, this will be the right side.
Examples
Basic usage:
let s = "\n Hello\tworld\t\n";
assert_eq!("Hello\tworld\t\n", s.trim_start());
Directionality:
let s = " English ";
assert!(Some('E') == s.trim_start().chars().next());
let s = " עברית ";
assert!(Some('ע') == s.trim_start().chars().next());
1.30.0 · sourcepub fn trim_end(&self) -> &str
pub fn trim_end(&self) -> &str
Returns a string slice with trailing whitespace removed.
‘Whitespace’ is defined according to the terms of the Unicode Derived
Core Property White_Space
, which includes newlines.
Text directionality
A string is a sequence of bytes. end
in this context means the last
position of that byte string; for a left-to-right language like English or
Russian, this will be right side, and for right-to-left languages like
Arabic or Hebrew, this will be the left side.
Examples
Basic usage:
let s = "\n Hello\tworld\t\n";
assert_eq!("\n Hello\tworld", s.trim_end());
Directionality:
let s = " English ";
assert!(Some('h') == s.trim_end().chars().rev().next());
let s = " עברית ";
assert!(Some('ת') == s.trim_end().chars().rev().next());
1.0.0 · sourcepub fn trim_left(&self) -> &str
👎Deprecated since 1.33.0: superseded by trim_start
pub fn trim_left(&self) -> &str
trim_start
Returns a string slice with leading whitespace removed.
‘Whitespace’ is defined according to the terms of the Unicode Derived
Core Property White_Space
.
Text directionality
A string is a sequence of bytes. ‘Left’ in this context means the first position of that byte string; for a language like Arabic or Hebrew which are ‘right to left’ rather than ‘left to right’, this will be the right side, not the left.
Examples
Basic usage:
let s = " Hello\tworld\t";
assert_eq!("Hello\tworld\t", s.trim_left());
Directionality:
let s = " English";
assert!(Some('E') == s.trim_left().chars().next());
let s = " עברית";
assert!(Some('ע') == s.trim_left().chars().next());
1.0.0 · sourcepub fn trim_right(&self) -> &str
👎Deprecated since 1.33.0: superseded by trim_end
pub fn trim_right(&self) -> &str
trim_end
Returns a string slice with trailing whitespace removed.
‘Whitespace’ is defined according to the terms of the Unicode Derived
Core Property White_Space
.
Text directionality
A string is a sequence of bytes. ‘Right’ in this context means the last position of that byte string; for a language like Arabic or Hebrew which are ‘right to left’ rather than ‘left to right’, this will be the left side, not the right.
Examples
Basic usage:
let s = " Hello\tworld\t";
assert_eq!(" Hello\tworld", s.trim_right());
Directionality:
let s = "English ";
assert!(Some('h') == s.trim_right().chars().rev().next());
let s = "עברית ";
assert!(Some('ת') == s.trim_right().chars().rev().next());
1.0.0 · sourcepub fn trim_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: DoubleEndedSearcher<'a>,
pub fn trim_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: DoubleEndedSearcher<'a>,
Returns a string slice with all prefixes and suffixes that match a pattern repeatedly removed.
The pattern can be a char
, a slice of char
s, or a function
or closure that determines if a character matches.
Examples
Simple patterns:
assert_eq!("11foo1bar11".trim_matches('1'), "foo1bar");
assert_eq!("123foo1bar123".trim_matches(char::is_numeric), "foo1bar");
let x: &[_] = &['1', '2'];
assert_eq!("12foo1bar12".trim_matches(x), "foo1bar");
A more complex pattern, using a closure:
assert_eq!("1foo1barXX".trim_matches(|c| c == '1' || c == 'X'), "foo1bar");
1.30.0 · sourcepub fn trim_start_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
pub fn trim_start_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
Returns a string slice with all prefixes that match a pattern repeatedly removed.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Text directionality
A string is a sequence of bytes. start
in this context means the first
position of that byte string; for a left-to-right language like English or
Russian, this will be left side, and for right-to-left languages like
Arabic or Hebrew, this will be the right side.
Examples
Basic usage:
assert_eq!("11foo1bar11".trim_start_matches('1'), "foo1bar11");
assert_eq!("123foo1bar123".trim_start_matches(char::is_numeric), "foo1bar123");
let x: &[_] = &['1', '2'];
assert_eq!("12foo1bar12".trim_start_matches(x), "foo1bar12");
1.45.0 · sourcepub fn strip_prefix<'a, P>(&'a self, prefix: P) -> Option<&'a str>where
P: Pattern<'a>,
pub fn strip_prefix<'a, P>(&'a self, prefix: P) -> Option<&'a str>where
P: Pattern<'a>,
Returns a string slice with the prefix removed.
If the string starts with the pattern prefix
, returns substring after the prefix, wrapped
in Some
. Unlike trim_start_matches
, this method removes the prefix exactly once.
If the string does not start with prefix
, returns None
.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Examples
assert_eq!("foo:bar".strip_prefix("foo:"), Some("bar"));
assert_eq!("foo:bar".strip_prefix("bar"), None);
assert_eq!("foofoo".strip_prefix("foo"), Some("foo"));
1.45.0 · sourcepub fn strip_suffix<'a, P>(&'a self, suffix: P) -> Option<&'a str>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn strip_suffix<'a, P>(&'a self, suffix: P) -> Option<&'a str>where
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
Returns a string slice with the suffix removed.
If the string ends with the pattern suffix
, returns the substring before the suffix,
wrapped in Some
. Unlike trim_end_matches
, this method removes the suffix exactly once.
If the string does not end with suffix
, returns None
.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Examples
assert_eq!("bar:foo".strip_suffix(":foo"), Some("bar"));
assert_eq!("bar:foo".strip_suffix("bar"), None);
assert_eq!("foofoo".strip_suffix("foo"), Some("foo"));
1.30.0 · sourcepub fn trim_end_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
pub fn trim_end_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
Returns a string slice with all suffixes that match a pattern repeatedly removed.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Text directionality
A string is a sequence of bytes. end
in this context means the last
position of that byte string; for a left-to-right language like English or
Russian, this will be right side, and for right-to-left languages like
Arabic or Hebrew, this will be the left side.
Examples
Simple patterns:
assert_eq!("11foo1bar11".trim_end_matches('1'), "11foo1bar");
assert_eq!("123foo1bar123".trim_end_matches(char::is_numeric), "123foo1bar");
let x: &[_] = &['1', '2'];
assert_eq!("12foo1bar12".trim_end_matches(x), "12foo1bar");
A more complex pattern, using a closure:
assert_eq!("1fooX".trim_end_matches(|c| c == '1' || c == 'X'), "1foo");
1.0.0 · sourcepub fn trim_left_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
👎Deprecated since 1.33.0: superseded by trim_start_matches
pub fn trim_left_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
trim_start_matches
Returns a string slice with all prefixes that match a pattern repeatedly removed.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Text directionality
A string is a sequence of bytes. ‘Left’ in this context means the first position of that byte string; for a language like Arabic or Hebrew which are ‘right to left’ rather than ‘left to right’, this will be the right side, not the left.
Examples
Basic usage:
assert_eq!("11foo1bar11".trim_left_matches('1'), "foo1bar11");
assert_eq!("123foo1bar123".trim_left_matches(char::is_numeric), "foo1bar123");
let x: &[_] = &['1', '2'];
assert_eq!("12foo1bar12".trim_left_matches(x), "foo1bar12");
1.0.0 · sourcepub fn trim_right_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
👎Deprecated since 1.33.0: superseded by trim_end_matches
pub fn trim_right_matches<'a, P>(&'a self, pat: P) -> &'a strwhere
P: Pattern<'a>,
<P as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
trim_end_matches
Returns a string slice with all suffixes that match a pattern repeatedly removed.
The pattern can be a &str
, char
, a slice of char
s, or a
function or closure that determines if a character matches.
Text directionality
A string is a sequence of bytes. ‘Right’ in this context means the last position of that byte string; for a language like Arabic or Hebrew which are ‘right to left’ rather than ‘left to right’, this will be the left side, not the right.
Examples
Simple patterns:
assert_eq!("11foo1bar11".trim_right_matches('1'), "11foo1bar");
assert_eq!("123foo1bar123".trim_right_matches(char::is_numeric), "123foo1bar");
let x: &[_] = &['1', '2'];
assert_eq!("12foo1bar12".trim_right_matches(x), "12foo1bar");
A more complex pattern, using a closure:
assert_eq!("1fooX".trim_right_matches(|c| c == '1' || c == 'X'), "1foo");
1.0.0 · sourcepub fn parse<F>(&self) -> Result<F, <F as FromStr>::Err>where
F: FromStr,
pub fn parse<F>(&self) -> Result<F, <F as FromStr>::Err>where
F: FromStr,
Parses this string slice into another type.
Because parse
is so general, it can cause problems with type
inference. As such, parse
is one of the few times you’ll see
the syntax affectionately known as the ‘turbofish’: ::<>
. This
helps the inference algorithm understand specifically which type
you’re trying to parse into.
parse
can parse into any type that implements the FromStr
trait.
Errors
Will return Err
if it’s not possible to parse this string slice into
the desired type.
Examples
Basic usage
let four: u32 = "4".parse().unwrap();
assert_eq!(4, four);
Using the ‘turbofish’ instead of annotating four
:
let four = "4".parse::<u32>();
assert_eq!(Ok(4), four);
Failing to parse:
let nope = "j".parse::<u32>();
assert!(nope.is_err());
1.23.0 · sourcepub fn is_ascii(&self) -> bool
pub fn is_ascii(&self) -> bool
Checks if all characters in this string are within the ASCII range.
Examples
let ascii = "hello!\n";
let non_ascii = "Grüße, Jürgen ❤";
assert!(ascii.is_ascii());
assert!(!non_ascii.is_ascii());
1.23.0 · sourcepub fn eq_ignore_ascii_case(&self, other: &str) -> bool
pub fn eq_ignore_ascii_case(&self, other: &str) -> bool
Checks that two strings are an ASCII case-insensitive match.
Same as to_ascii_lowercase(a) == to_ascii_lowercase(b)
,
but without allocating and copying temporaries.
Examples
assert!("Ferris".eq_ignore_ascii_case("FERRIS"));
assert!("Ferrös".eq_ignore_ascii_case("FERRöS"));
assert!(!"Ferrös".eq_ignore_ascii_case("FERRÖS"));
1.34.0 · sourcepub fn escape_debug(&self) -> EscapeDebug<'_>
pub fn escape_debug(&self) -> EscapeDebug<'_>
Return an iterator that escapes each char in self
with char::escape_debug
.
Note: only extended grapheme codepoints that begin the string will be escaped.
Examples
As an iterator:
for c in "❤\n!".escape_debug() {
print!("{c}");
}
println!();
Using println!
directly:
println!("{}", "❤\n!".escape_debug());
Both are equivalent to:
println!("❤\\n!");
Using to_string
:
assert_eq!("❤\n!".escape_debug().to_string(), "❤\\n!");
1.34.0 · sourcepub fn escape_default(&self) -> EscapeDefault<'_>
pub fn escape_default(&self) -> EscapeDefault<'_>
Return an iterator that escapes each char in self
with char::escape_default
.
Examples
As an iterator:
for c in "❤\n!".escape_default() {
print!("{c}");
}
println!();
Using println!
directly:
println!("{}", "❤\n!".escape_default());
Both are equivalent to:
println!("\\u{{2764}}\\n!");
Using to_string
:
assert_eq!("❤\n!".escape_default().to_string(), "\\u{2764}\\n!");
1.34.0 · sourcepub fn escape_unicode(&self) -> EscapeUnicode<'_>
pub fn escape_unicode(&self) -> EscapeUnicode<'_>
Return an iterator that escapes each char in self
with char::escape_unicode
.
Examples
As an iterator:
for c in "❤\n!".escape_unicode() {
print!("{c}");
}
println!();
Using println!
directly:
println!("{}", "❤\n!".escape_unicode());
Both are equivalent to:
println!("\\u{{2764}}\\u{{a}}\\u{{21}}");
Using to_string
:
assert_eq!("❤\n!".escape_unicode().to_string(), "\\u{2764}\\u{a}\\u{21}");
1.0.0 · sourcepub fn replace<'a, P>(&'a self, from: P, to: &str) -> Stringwhere
P: Pattern<'a>,
pub fn replace<'a, P>(&'a self, from: P, to: &str) -> Stringwhere
P: Pattern<'a>,
Replaces all matches of a pattern with another string.
replace
creates a new String
, and copies the data from this string slice into it.
While doing so, it attempts to find matches of a pattern. If it finds any, it
replaces them with the replacement string slice.
Examples
Basic usage:
let s = "this is old";
assert_eq!("this is new", s.replace("old", "new"));
assert_eq!("than an old", s.replace("is", "an"));
When the pattern doesn’t match:
let s = "this is old";
assert_eq!(s, s.replace("cookie monster", "little lamb"));
1.16.0 · sourcepub fn replacen<'a, P>(&'a self, pat: P, to: &str, count: usize) -> Stringwhere
P: Pattern<'a>,
pub fn replacen<'a, P>(&'a self, pat: P, to: &str, count: usize) -> Stringwhere
P: Pattern<'a>,
Replaces first N matches of a pattern with another string.
replacen
creates a new String
, and copies the data from this string slice into it.
While doing so, it attempts to find matches of a pattern. If it finds any, it
replaces them with the replacement string slice at most count
times.
Examples
Basic usage:
let s = "foo foo 123 foo";
assert_eq!("new new 123 foo", s.replacen("foo", "new", 2));
assert_eq!("faa fao 123 foo", s.replacen('o', "a", 3));
assert_eq!("foo foo new23 foo", s.replacen(char::is_numeric, "new", 1));
When the pattern doesn’t match:
let s = "this is old";
assert_eq!(s, s.replacen("cookie monster", "little lamb", 10));
1.2.0 · sourcepub fn to_lowercase(&self) -> String
pub fn to_lowercase(&self) -> String
Returns the lowercase equivalent of this string slice, as a new String
.
‘Lowercase’ is defined according to the terms of the Unicode Derived Core Property
Lowercase
.
Since some characters can expand into multiple characters when changing
the case, this function returns a String
instead of modifying the
parameter in-place.
Examples
Basic usage:
let s = "HELLO";
assert_eq!("hello", s.to_lowercase());
A tricky example, with sigma:
let sigma = "Σ";
assert_eq!("σ", sigma.to_lowercase());
// but at the end of a word, it's ς, not σ:
let odysseus = "ὈΔΥΣΣΕΎΣ";
assert_eq!("ὀδυσσεύς", odysseus.to_lowercase());
Languages without case are not changed:
let new_year = "农历新年";
assert_eq!(new_year, new_year.to_lowercase());
1.2.0 · sourcepub fn to_uppercase(&self) -> String
pub fn to_uppercase(&self) -> String
Returns the uppercase equivalent of this string slice, as a new String
.
‘Uppercase’ is defined according to the terms of the Unicode Derived Core Property
Uppercase
.
Since some characters can expand into multiple characters when changing
the case, this function returns a String
instead of modifying the
parameter in-place.
Examples
Basic usage:
let s = "hello";
assert_eq!("HELLO", s.to_uppercase());
Scripts without case are not changed:
let new_year = "农历新年";
assert_eq!(new_year, new_year.to_uppercase());
One character can become multiple:
let s = "tschüß";
assert_eq!("TSCHÜSS", s.to_uppercase());
1.16.0 · sourcepub fn repeat(&self, n: usize) -> String
pub fn repeat(&self, n: usize) -> String
Creates a new String
by repeating a string n
times.
Panics
This function will panic if the capacity would overflow.
Examples
Basic usage:
assert_eq!("abc".repeat(4), String::from("abcabcabcabc"));
A panic upon overflow:
// this will panic at runtime
let huge = "0123456789abcdef".repeat(usize::MAX);
1.23.0 · sourcepub fn to_ascii_uppercase(&self) -> String
pub fn to_ascii_uppercase(&self) -> String
Returns a copy of this string where each character is mapped to its ASCII upper case equivalent.
ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.
To uppercase the value in-place, use make_ascii_uppercase
.
To uppercase ASCII characters in addition to non-ASCII characters, use
to_uppercase
.
Examples
let s = "Grüße, Jürgen ❤";
assert_eq!("GRüßE, JüRGEN ❤", s.to_ascii_uppercase());
1.23.0 · sourcepub fn to_ascii_lowercase(&self) -> String
pub fn to_ascii_lowercase(&self) -> String
Returns a copy of this string where each character is mapped to its ASCII lower case equivalent.
ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.
To lowercase the value in-place, use make_ascii_lowercase
.
To lowercase ASCII characters in addition to non-ASCII characters, use
to_lowercase
.
Examples
let s = "Grüße, Jürgen ❤";
assert_eq!("grüße, jürgen ❤", s.to_ascii_lowercase());
Trait Implementations§
source§impl Ord for Class
impl Ord for Class
source§impl PartialOrd<Class> for Class
impl PartialOrd<Class> for Class
1.0.0 · source§fn le(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
self
and other
) and is used by the <=
operator. Read more