api: Remove the NNG_FLAG_ALLOC

This flag failed to provide real zero copy that it was intended for,
and it also involved extra allocations.  Further, the API for it was
brittle and error prone.

Modern code should just work directly with nng_msg structures.

1 files changed, 1 insertions, 3 deletions

diff --git a/docs/ref/api/memory.md b/docs/ref/api/memory.md
index c5ecb23a..d8c5ecf9 100644
--- a/docs/ref/api/memory.md
+++ b/docs/ref/api/memory.md
@@ -19,9 +19,7 @@ Note that the memory may have random data in it, just like with `malloc`.
 If memory cannot be allocated for any reason, then `NULL` will be returned.
 Applications that experience this should treat this like [`NNG_ENOMEM`].
 
-Memory returned by `nng_alloc` can be used to hold message buffers, in which
-case it can be directly passed to [`nng_send`] using the flag `NNG_FLAG_ALLOC`.
-Alternatively, it can be freed when no longer needed using [`nng_free`].
+Memory returned by `nng_alloc` should be freed when no longer needed using [`nng_free`].
 
 > [!IMPORTANT]
 > Do not use the system `free` function (or the C++ `delete` operator) to release this memory.