The Handle_Return_Ref specialization for const references was wrapping
return values in std::cref() while marking them as return values
(is_return_value=true). This caused Vector.push_back() to store the
reference directly without cloning, since it assumes return values are
freshly created temporaries. When the source object (e.g., a map) went
out of scope, the vector contained dangling references to freed memory.
The fix sets is_return_value=false for const reference returns, which
correctly triggers push_back to clone the value instead of storing a
bare reference. This is consistent with the non-const reference handler
(Handle_Return<Ret &>) which also does not set the return value flag.
Co-authored-by: leftibot <leftibot@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
