Struct warts::Flags

source · []
pub struct Flags { /* private fields */ }
Expand description

A variable length flag structure.

From the warts(5) man page:

The warts routines in scamper provide the ability to conditionally store arbitrary data in a forwards compatible method. A set of flags and parameters begins with a sequence of bytes that denote which items are included. If any flags are set, then after the flags is a 2-byte field that records the length of the parameters that follow. Finally, the data follows. The following figure illustrates how flags are recorded:

   Byte zero           Byte one          Byte two
 8 7 6 5 4 3 2 1    8 7 6 5 4 3 2 1   8 7 6 5 4 3 2 1
+-+-+-+-+-+-+-+-+  +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|1              |  |1              | |0              |
+-+-+-+-+-+-+-+-+  +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+

The most significant bit of each byte is the `link’ bit; it determines if the next byte in the sequence contains flags. The low-order 7 bits of each byte signal if the corresponding field is written out in the parameters that follow. In the figure, the link bit is set to one in the first two bytes, and zero in the final byte, signifying that three flag-bytes are included.

The rest of each byte is used to record flags, whose position in the sequence signifies if a particular parameter is included. For example, if bit 6 of byte zero is set, then parameter 6 is included, and if bit 5 of byte one is set, then parameter 12 is included, and if bit 2 of byte two is set, then parameter 16 is included.

Implementations

Initialize flags from a 64-bit bitfield.

Initialize flags from a byte slice and return the number of bytes read.

Returns a byte vector representing the VLQ-encoded flags.

Returns true if at-least one flag is set to 1.

Returns true if the specified flag is set to 1. Note that flags indices start at 1.

Trait Implementations

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

Read bits and construct type Read more

Write type to bits Read more

Converts to this type from the input type.

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

Returns the size of the binary representation of the type in a warts object.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Converts self into T using Into<T>. Read more

Causes self to use its Binary implementation when Debug-formatted.

Causes self to use its Display implementation when Debug-formatted. Read more

Causes self to use its LowerExp implementation when Debug-formatted. Read more

Causes self to use its LowerHex implementation when Debug-formatted. Read more

Causes self to use its Octal implementation when Debug-formatted.

Causes self to use its Pointer implementation when Debug-formatted. Read more

Causes self to use its UpperExp implementation when Debug-formatted. Read more

Causes self to use its UpperHex implementation when Debug-formatted. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Pipes by value. This is generally the method you want to use. Read more

Borrows self and passes that borrow into the pipe function. Read more

Mutably borrows self and passes that borrow into the pipe function. Read more

Borrows self, then passes self.borrow() into the pipe function. Read more

Mutably borrows self, then passes self.borrow_mut() into the pipe function. Read more

Borrows self, then passes self.as_ref() into the pipe function.

Mutably borrows self, then passes self.as_mut() into the pipe function. Read more

Borrows self, then passes self.deref() into the pipe function.

Mutably borrows self, then passes self.deref_mut() into the pipe function. Read more

Immutable access to a value. Read more

Mutable access to a value. Read more

Immutable access to the Borrow<B> of a value. Read more

Mutable access to the BorrowMut<B> of a value. Read more

Immutable access to the AsRef<R> view of a value. Read more

Mutable access to the AsMut<R> view of a value. Read more

Immutable access to the Deref::Target of a value. Read more

Mutable access to the Deref::Target of a value. Read more

Calls .tap() only in debug builds, and is erased in release builds.

Calls .tap_mut() only in debug builds, and is erased in release builds. Read more

Calls .tap_borrow() only in debug builds, and is erased in release builds. Read more

Calls .tap_borrow_mut() only in debug builds, and is erased in release builds. Read more

Calls .tap_ref() only in debug builds, and is erased in release builds. Read more

Calls .tap_ref_mut() only in debug builds, and is erased in release builds. Read more

Calls .tap_deref() only in debug builds, and is erased in release builds. Read more

Calls .tap_deref_mut() only in debug builds, and is erased in release builds. Read more

Attempts to convert self into T using TryInto<T>. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.