[Sunrisepeak]

Zstandard 1.5.7 as C++23 modules over compat.zstd 1.5.7, the first release of the mwrap identity mcpplibs.mwrap.zstd (mcpp-index docs/mwrap.md). mcpp 2026.11.7.1 imports it in place of including <zstd.h> (mcpp design record 2026-11-07, D10).

Contents

• mcpplibs.mwrap.zstd: the stable API of <zstd.h> and the error codes of <zstd_errors.h>: 68 functions, 21 types, 97 enumerators, upstream names in the global namespace. The experimental section (ZSTD_STATIC_LINKING_ONLY) and <zdict.h> (not built by compat.zstd) are not exported; docs/usage.md says why.
• mcpplibs.mwrap.zstd.macros: 15 constant macros, same names, in mcpplibs::mwrap::zstd::macros.
• <mwrap/zstd/macros.hpp>: ZSTD_COMPRESSBOUND, upstream's definition.
• tools/generate.py writes these four files from the headers as clang reads them with the build's flags; --check audits them on every LLVM row. tools/surface.toml lists the declaration-syntax macros.
• Tests: one-shot round trip, level-19 frame whose damaged checksum is ZSTD_error_checksum_wrong, a stream in pieces, a raw-content dictionary, the error code of garbage, version and bound against their macros, every constant against its macro, header mixing. Four upstream examples over the same library. Default template squeeze, scaffolded as an installed package.

Local results (Linux x86_64)

Check	Result
mcpp test, GCC 16.1.0 / LLVM 23.1.3 / GCC 16.1.0 --target x86_64-linux-musl	3/3 passed each
tools/generate.py --check	0 problems
tools/run_conformance.py	the examples round-trip
tools/test_template.py	template built and ran
tools/check_mwrap_release.py	mcpplibs.mwrap.zstd@1.5.7

After merge: tag mwrap-1.5.7, GitCode mirror, mcpp-index pkgs/mwrap/zstd.lua and tests/mwrap/zstd.