Proxy 4.1.0 Release

Proxy 4.1.0 is a focused feature-and-ergonomics release. It smooths out the authoring experience, delivers dramatic compile-time speedups, adds a low-level dispatch optimization hook, and broadens portability to freestanding environments and Bazel. All while staying source-compatible with 4.0.x.

What's inside

Ergonomics and API

• Unqualified invoke and reflect. pro::proxy and pro::proxy_indirect_accessor now expose invoke and reflect as hidden friend functions, so dispatch and reflector authors no longer need to qualify their calls. proxy_invoke and proxy_reflect are deprecated in favor of the unqualified forms. (#23)
• A clearer facade-composition API. New add_facade_with_substitution on basic_facade_builder says what it does at the call site, replacing the terse add_facade<F, true>. (#27)
• New optimization hook: reinterpret_invoke. When the concrete contained pointer type is already known at a call site, reinterpret_invoke dispatches directly against that type: no type erasure, no runtime metadata lookup, no virtual call. Reach for it on hot paths or when authoring custom dispatch types and accessors. Ordinary code should still prefer invoke. (#36)
• Clearer diagnostics. A facade with an ill-formed facade-aware overload now produces a focused, actionable error instead of a cascade of unrelated failures. (#29)
• The feature-test macro __msft_lib_proxy is now 202606L.

Performance

• Convention-heavy facades compile dramatically faster: roughly +29% with 10 conventions, +71% with 30, and up to ~8.5× with 200. A special thanks to @Kim-J-Smith for his insights. (#32)

Portability

• First-class Bazel support. Proxy now integrates with Bazel alongside CMake and Meson. Bzlmod (Bazel 7+) is the recommended path (bazel_dep(name = "proxy", version = "4.1.0")). Legacy WORKSPACE mode is supported back to Bazel 5.1+. See README.md for setup. (#40)
• Freestanding modules support. Proxy is now validated in freestanding environments, including its C++20 module, with coverage across all three build systems. (#49)
• Built-in compatibility guards. Proxy emits a clear error on pre-C++20 compilers and actively guards against a known clang-cl miscompile (llvm/llvm-project#143245) that could otherwise silently corrupt pro::proxy. (#50)

Tooling and CI

• Aligned CMake/Meson build configuration and made doc-example testing reconfigure promptly when docs change. (#39)
• Added pre-commit hooks, a CONTRIBUTING.md, and a lint CI job. (#41)
• Stood up automated weekly dependency updates (self-hosted Renovate plus a companion script for CMake/Meson pins). (#43, #46, #47, #48)
• Refreshed toolchains and dependencies: Clang 22, NVHPC 26.3, Google Benchmark 1.9.5, a Clang 21 regression job, and assorted action/dependency bumps. (#25, #44, #52, #31, #22)
• Fixed a benchmark bug that also improved the reported numbers. (#26)

Deprecations

Deprecated APIs still compile and work; they emit deprecation warnings.

Deprecated	Use instead
proxy_invoke / proxy_reflect	unqualified invoke / reflect
add_facade<F, true>	add_facade_with_substitution

Upgrading

Most users can update to 4.1.0 and rebuild while public APIs are source-compatible. The deprecated APIs above still compile and work. Migrate to their replacements at your convenience to silence the warnings.

Full Changelog: 4.0.2...4.1.0