__FILE__/__LINE__ are preprocessor macros - as default argument values
in the header they expand once, at the header declaration site, not at
each call site. Every throw relying on the defaults (all but File.cpp,
which passed them explicitly) reported Exception.h itself instead of
the real error location.
Switched the defaults to std::source_location::current(), which the
C++20 standard specifically defines to evaluate at the call site when
used as a default argument - unlike macros. Kept the same 4-parameter
signature so every existing call site, including ones that pass
__FILE__/__LINE__ explicitly, is unaffected.
Verified two ways: full-repo compile pass (identical result to before,
13/20 clean, same pre-existing StreamReader.h-blocked failures, nothing
new broken); a real runtime test - a throw relying on defaults from a
known line correctly reported that exact file/line via the caught
exceptions .file/.line members. Test file not included in this commit.
Brad Arant
barant