gcc-14 CI tests failing in mixed_optional

Start with libs/contract/test/result/mixed_optional.hpp and reproduce the gcc-14, C++11 test named in the failure output. Inspect the constructor/destructor count assertions at lines 271, 316, 353, and 406 alongside their surrounding cases. Done means the mixed_optional test passes under gcc-14 without the four count mismatches.

testing.capture-output bin.v2/libs/contract/test/result-mixed_optional.test/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden/result-mixed_optional.run
====== BEGIN OUTPUT ======
d::static_inv
d::inv
c::static_inv
c::inv
b::static_inv
b::inv
a::static_inv
a::inv
d::f::pre
c::f::pre
b::f::pre
a::f::pre
d::f::old
c::f::old
b::f::old
a::f::old
a::f::body
d::static_inv
d::inv
c::static_inv
c::inv
b::static_inv
b::inv
a::static_inv
a::inv
d::f::old
d::f::post
c::f::old
c::f::post
b::f::old
b::f::post
a::f::post
libs/contract/test/result/mixed_optional.hpp(271): test 'ch_type::ctors() == ch_type::dtors() + ch_extras' ('9' == '3') failed in function 'int main()'
d::static_inv
d::inv
c::static_inv
c::inv
b::static_inv
b::inv
d::f::pre
c::f::pre
b::f::pre
d::f::old
c::f::old
b::f::old
b::f::body
d::static_inv
d::inv
c::static_inv
c::inv
b::static_inv
b::inv
d::f::old
d::f::post
c::f::old
c::f::post
b::f::post
libs/contract/test/result/mixed_optional.hpp(316): test 'ch_type::ctors() == ch_type::dtors() + ch_extras' ('11' == '5') failed in function 'int main()'
d::static_inv
d::inv
c::static_inv
c::inv
d::f::pre
c::f::pre
d::f::old
c::f::old
c::f::body
d::static_inv
d::inv
c::static_inv
c::inv
d::f::old
d::f::post
c::f::post
libs/contract/test/result/mixed_optional.hpp(353): test 'ch_type::ctors() == ch_type::dtors() + ch_extras' ('13' == '7') failed in function 'int main()'
d::static_inv
d::inv
c::static_inv
c::inv
b::static_inv
b::inv
e::static_inv
e::inv
d::f::pre
c::f::pre
b::f::pre
e::f::pre
d::f::old
c::f::old
b::f::old
e::f::old
e::f::body
d::static_inv
d::inv
c::static_inv
c::inv
b::static_inv
b::inv
e::static_inv
e::inv
d::f::old
d::f::post
c::f::old
c::f::post
b::f::old
b::f::post
e::f::post
libs/contract/test/result/mixed_optional.hpp(406): test 'ch_type::ctors() == ch_type::dtors() + ch_extras' ('21' == '9') failed in function 'int main()'
4 errors detected.

EXIT STATUS: 4
====== END OUTPUT ======

LD_LIBRARY_PATH="/home/runner/work/contract/boost-root/bin.v2/libs/atomic/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/home/runner/work/contract/boost-root/bin.v2/libs/chrono/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/home/runner/work/contract/boost-root/bin.v2/libs/container/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/home/runner/work/contract/boost-root/bin.v2/libs/contract/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/home/runner/work/contract/boost-root/bin.v2/libs/date_time/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/home/runner/work/contract/boost-root/bin.v2/libs/iostreams/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/home/runner/work/contract/boost-root/bin.v2/libs/random/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/home/runner/work/contract/boost-root/bin.v2/libs/regex/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/home/runner/work/contract/boost-root/bin.v2/libs/system/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/home/runner/work/contract/boost-root/bin.v2/libs/thread/build/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden:/usr/bin:/usr/lib:/usr/lib32:/usr/lib64:$LD_LIBRARY_PATH"

export LD_LIBRARY_PATH

 "bin.v2/libs/contract/test/result-mixed_optional.test/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden/result-mixed_optional"   > "bin.v2/libs/contract/test/result-mixed_optional.test/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden/result-mixed_optional.output" 2>&1 < /dev/null
status=$?
echo >> "bin.v2/libs/contract/test/result-mixed_optional.test/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden/result-mixed_optional.output"
echo EXIT STATUS: $status >> "bin.v2/libs/contract/test/result-mixed_optional.test/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden/result-mixed_optional.output"
if test $status -eq 0 ; then
    cp "bin.v2/libs/contract/test/result-mixed_optional.test/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden/result-mixed_optional.output" "bin.v2/libs/contract/test/result-mixed_optional.test/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden/result-mixed_optional.run" >/dev/null
fi
verbose=0
if test $status -ne 0 ; then
    verbose=1
fi
if test $verbose -eq 1 ; then
    echo ====== BEGIN OUTPUT ======
    cat "bin.v2/libs/contract/test/result-mixed_optional.test/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden/result-mixed_optional.output"
    echo ====== END OUTPUT ======
fi
exit $status

...failed testing.capture-output bin.v2/libs/contract/test/result-mixed_optional.test/gcc-14/release/x86_64/cxxstd-11-iso/threading-multi/visibility-hidden/result-mixed_optional.run...