DoxigAlpha

resize

Request to modify the size of an allocation.

It is guaranteed to not move the pointer, however the allocator implementation may refuse the resize request by returning false.

allocation may be an empty slice, in which case a new allocation is made.

new_len may be zero, in which case the allocation is freed.

Function parameters

Parameters

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allocation:anytype
new_len:usize

Type definitions in this namespace

Types

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Functions in this namespace

Functions

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rawAlloc
This function is not intended to be called except from within the
rawResize
This function is not intended to be called except from within the
rawRemap
This function is not intended to be called except from within the
rawFree
This function is not intended to be called except from within the
create
Returns a pointer to undefined memory.
destroy
`ptr` should be the return value of `create`, or otherwise
alloc
Allocates an array of `n` items of type `T` and sets all the
allocSentinel
Allocates an array of `n + 1` items of type `T` and sets the first `n`
resize
Request to modify the size of an allocation.
remap
Request to modify the size of an allocation, allowing relocation.
realloc
This function requests a new size for an existing allocation, which
free
Free an array allocated with `alloc`.
dupe
Copies `m` to newly allocated memory.
dupeZ
Copies `m` to newly allocated memory, with a null-terminated element.

Error sets in this namespace

Error Sets

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Source

Implementation

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pub fn resize(self: Allocator, allocation: anytype, new_len: usize) bool {
    const Slice = @typeInfo(@TypeOf(allocation)).pointer;
    const T = Slice.child;
    const alignment = Slice.alignment;
    if (new_len == 0) {
        self.free(allocation);
        return true;
    }
    if (allocation.len == 0) {
        return false;
    }
    const old_memory = mem.sliceAsBytes(allocation);
    // I would like to use saturating multiplication here, but LLVM cannot lower it
    // on WebAssembly: https://github.com/ziglang/zig/issues/9660
    //const new_len_bytes = new_len *| @sizeOf(T);
    const new_len_bytes = math.mul(usize, @sizeOf(T), new_len) catch return false;
    return self.rawResize(old_memory, .fromByteUnits(alignment), new_len_bytes, @returnAddress());
}