A simple iterator for packing/unpacking primitive c types to/from a provided buffer.
/* A buffer to store packed data */
uint8_t buf[6];
/* Construct a new cursor with the buffer we just defined */
struct cursor csr = cursor_new(buf, sizeof(buf));
uint16_t written_u16 = 0x0123;
uint32_t written_u32 = 0x456789AB;
/* Write written_u16 to buf little-endian */
cursor_pack_le(&csr, written_u16);
/* Write written_u32 to buf big-endian */
cursor_pack_be(&csr, written_u32);
/* Reset csr */
csr = cursor_new(buf, sizeof(buf));
uint16_t read_u16 = 0;
uint32_t read_u32 = 0;
/* Read a packed little-endian uint16_t out of buf */
cursor_unpack_le(&csr, &read_u16);
/* Read a packed big-endian uint32_t out of buf */
cursor_unpack_be(&csr, &read_u32);
assert(read_u16 == written_u16);
assert(read_u32 == written_u32);
See the full example.
cursor
makes use of c11's generic selection expression feature. These are the minimum gcc
and clang
versions that support it:
- clang >= 3.8
- gcc >= 4.9
Feel free to open an issue if you'd like to use cursor
but you're compiler is not compatible. The generic pack/unpack function calls are just sugar, and a configuration step could ifdef
them out when not supported.