span - CTL - C Container Template library

Defined in header <ctl/span.h>, CTL prefix span.

SYNOPSIS

#define T int
#include <ctl/span.h>

int values[] = {1, 2, 3, 4, 5};
span_int view = span_int_init(values, 5);
span_int tail = span_int_subspan(&view, 1, 3);
for (int *it = span_int_begin(&view); it != span_int_end(&view); it++)
  printf("%d ", *it);

DESCRIPTION

span (comparable to C++20 std::span) is a non-owning view over a contiguous run of T. It stores only a pointer and a size; it never allocates, copies, or frees. The viewed storage — a plain array, a vector’s data(), an array’s storage, or any other contiguous buffer — must outlive the span.

The function names are composed of the prefix span_, the user-defined type T and the method name. E.g. span_int with #define T int.

Member functions

A init (T* data, size_t size)

constructs a view over [data, data + size).

Element access

T* data (A* self)
T* at (A* self, size_t index)      // asserts in-range
T* front (A* self)
T* back (A* self)

Iterators

T* begin (A* self)
T* end (A* self)

Plain pointers; usable directly in a for loop or with <ctl/algorithm.h> pointer ranges.

Capacity

int empty (A* self)

size and capacity are the size struct field directly; there is no growth, so no separate accessor is needed beyond reading self->size.

Views

A subspan (A* self, size_t offset, size_t count)

a view over [offset, offset + count). count is clamped to the available length, so passing SIZE_MAX yields “to the end”.

A first (A* self, size_t count)
A last (A* self, size_t count)

the leading/trailing count elements.