Trait cstr_argument::CStrArgument
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[src]
pub trait CStrArgument: Debug + Sized { type Output: AsRef<CStr>; fn try_into_cstr(self) -> Result<Self::Output, NulError<Self>>; fn into_cstr(self) -> Self::Output { ... } }
A trait for converting function arguments to null terminated strings. It can be used to convert string arguments that are passed on to C APIs using the minimal amount of allocations.
Strings that are already null terminated are just wrapped in a CStr without any allocations. Strings that are not already null terminated are converted to a CString possibly requiring one or more allocations. Trying to convert strings with a null byte in any position other than the final will result in an error.
Example
use std::os::raw::c_char; use cstr_argument::CStrArgument; extern "C" { fn foo(s: *const c_char); } fn bar<S: CStrArgument>(s: S) { let s = s.into_cstr(); unsafe { foo(s.as_ref().as_ptr()) } } fn baz() { bar("hello "); // Argument will be converted to a CString requiring an allocation bar("world\0"); // Argument will be converted to a CStr without any allocations bar("!".to_owned()); // Argument will be converted to a CString possibly requiring an // allocation }
Associated Types
type Output: AsRef<CStr>
The type of the string after conversion. The type may or may not own the resulting string.
Required Methods
fn try_into_cstr(self) -> Result<Self::Output, NulError<Self>>
Returns the string with a null terminator or an error.
Errors
This function will return an error if the string contains a null byte at any position other than the final.
Provided Methods
fn into_cstr(self) -> Self::Output
Returns the string with a null terminator.
Panics
This function will panic if the string contains a null byte at any position other
than the final. See try_into_cstr for a non-panicking version
of this function.