This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 118e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
2025-11-05
[Moved to DR at the October, 2015 meeting.]
According to 7.3 [conv] paragraph 5,
Certain language constructs require conversion to a valuehaving one of a specified set of types appropriate to theconstruct. An expressione of class typeEappearing in such a context is said to becontextuallyimplicitly converted to a specified typeT andis well-formed if and only ife can be implicitlyconverted to a typeT that is determined asfollows:E is searched for conversion functionswhose return type iscvT or referencetocvT such thatT is allowed bythe context. There shall be exactly one suchT.
This description leaves open two questions: first, canexplicit conversion functions be used for thisconversion? Second, assuming that they cannot, is therestriction to “exactly one suchT”enforced before or after exclusion ofexplicitconversion functions?
Notes from the November, 2014 meeting:
CWG felt thatexplicit conversion functions shouldbe removed from consideration before determining the set oftypes for the conversion.
Proposed resolution (May, 2015):
Change 7.3 [conv] paragraph 5 as follows:
...An expressione of class typeEappearing in such a context is said to becontextuallyimplicitly converted to a specified typeT andis well-formed if and only ife can be implicitlyconverted to a typeT that is determined asfollows:E is searched fornon-explicitconversion functions whose return typeiscvT or reference tocvTsuch thatT is allowed by the context. There shallbe exactly one suchT.