Annex C (informative) Compatibility [diff]

C.2 C++ and ISO C++ 2003 [diff.cpp03]

C.2.12 Clause [strings]: strings library [diff.cpp03.strings]

[string.classes]
Change: basic_string requirements no longer allow reference-counted strings
Rationale: Invalidation is subtly different with reference-counted strings. This change regularizes behavior for this International Standard.
Effect on original feature: Valid C++ 2003 code may execute differently in this International Standard.

[string.require]
Change: Loosen basic_string invalidation rules
Rationale: Allow small-string optimization.
Effect on original feature: Valid C++ 2003 code may execute differently in this International Standard. Some const member functions, such as data and c_str, no longer invalidate iterators.