Fix sstream_convert for types not constructible from const char*#418
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The sstream_convert template constructed the destination type via To to(ss.str().c_str()), which only works when To accepts a const char* (e.g. mpf_class). Instantiations with To = double, used in tests/unit/test-core-ints.cc, fail to compile under gcc 16. Dispatch via SFINAE: keep the c_str() construction for types that accept const char*, and use stream extraction (To to; ss >> to;) for all others. Fixes evaleev#417 Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
evaleev
approved these changes
May 20, 2026
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Summary
sstream_convert<To>constructs the destination asTo to(ss.str().c_str()), which only compiles whenToaccepts aconst char*(e.g.mpf_class). Instantiations withTo = doublefromtests/unit/test-core-ints.ccfail to compile under gcc 16.c_str()construction for types constructible fromconst char*(preserves the existingmpf_classprecision-via-string path), and use stream extraction (To to; ss >> to;) for everything else (double, etc.).Fixes #417
Test plan
unit_tests-libint2builds with gcc 16 andLIBINT_HAS_MPFR=1libint2/unit/runandlibint2/unit/sho=gaussian/runctest targets pass🤖 Generated with Claude Code