On Apr 16, 2026, at 7:27 AM, Marshall Clow <mclow.lists@gmail.com> wrote:
The first release candidates for the 1.91.0 release are now available at: <https://archives.boost.io/release/1.91.0/source/>
The SHA256 checksums are as follows:
9446c37fd86fecd95254ebe5d368a66ef9b09cec4592b2746979076657e24e65 boost_1_91_0_rc1.7z 5734305f40a76c30f951c9abd409a45a2a19fb546efe4162119250bbe4d3a463 boost_1_91_0_rc1.tar.gz 69c6f32fbda3c478fb310ec251e6699e5e584dbc71afb5425c2f6e98c9540a77 boost_1_91_0_rc1.zip de5e6b0e4913395c6bdfa90537febd9028ea4c0735d2cdb0cd9b45d5f51264f5 boost_1_91_0_rc1.tar.bz2
As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy.
I have successfully built the boost libraries on an M4Pro Mac Mini with Apple clang version 21.0.0 (clang-2100.0.123.102) There are significantly more warnings than the previous release. In particular, there are over 3000 warnings of the form: ./boost/proto/transform/detail/preprocessed/call.hpp:12:23: warning: declaration of a variadic function without a comma before '...' is deprecated [-Wdeprecated-missing-comma-variadic-parameter] 12 | struct call<Fun(A0...)> : transform<call<Fun(A0...)> > | ^ | , ./boost/proto/transform/detail/preprocessed/call.hpp:12:52: warning: declaration of a variadic function without a comma before '...' is deprecated [-Wdeprecated-missing-comma-variadic-parameter] 12 | struct call<Fun(A0...)> : transform<call<Fun(A0...)> > | ^ | , ./boost/proto/transform/detail/preprocessed/call.hpp:32:28: warning: declaration of a variadic function without a comma before '...' is deprecated [-Wdeprecated-missing-comma-variadic-parameter] 32 | struct call<Fun(A0 , A1...)> : transform<call<Fun(A0 , A1...)> > (C++2c only) — Marshall