[ 2017-03-04, Kona ]

We believe that [member.functions]p2 is clear.

Section [member.functions] makes it clear that standard library implementers are allowed to "replace a member function with default arguments with two or more member functions with equivalent behavior". However, it is unclear when reading [global.functions] whether implementers are allowed to perform the same transformation for non-member functions. [global.functions] p3 mentions that "an implementation shall not declare a non-member function signature with additional default arguments", but does not explicitly forbid to replace a function with default arguments with more functions with equivalent behavior.

The standard should make it clear whether such a transformation is conforming or not, probably through a note [global.functions].

Link to the Standard Discussion forum.