12 Overloading [over]

If the postfix-expression E in the function call syntax evaluates to a class object of type “cv T”, then the set of candidate functions includes at least the function call operators of T.

The function call operators of T are obtained by ordinary lookup of the name operator() in the context of (E).operator().

In addition, for each non-explicit conversion function declared in T of the form where the optional cv-qualifier-seq is the same cv-qualification as, or a greater cv-qualification than, cv, and where conversion-type-id denotes the type “pointer to function of (${\text{P}}_1,\dots ,{\text{P}}_n$) returning R”, or the type “reference to pointer to function of (${\text{P}}_1,\dots ,{\text{P}}_n$) returning R”, or the type “reference to function of (${\text{P}}_1,\dots ,{\text{P}}_n$) returning R”, a surrogate call function with the unique name call-function and having the form is also considered as a candidate function.

Similarly, surrogate call functions are added to the set of candidate functions for each non-explicit conversion function declared in a base class of T provided the function is not hidden within T by another intervening declaration.124

The argument list submitted to overload resolution consists of the argument expressions present in the function call syntax preceded by the implied object argument (E).