SYNOPSIS
#include <nng/nng.h>
int nng_msg_header_append(nng_msg *msg, const void *val, size_t size);
int nng_msg_header_append_u32(nng_msg *msg, uint32_t val32);DESCRIPTION
The nng_msg_header_append() and nng_msg_header_append_u32()
functions append data to
the end of the headers of message msg, reallocating it if necessary.
The first function appends size bytes, copying them from val. The
second function appends the value val32 in network-byte order (big-endian).
RETURN VALUES
This function returns 0 on success, and non-zero otherwise.
ERRORS
NNG_ENOMEM-
Insufficient free memory exists.