postfix-expression ( expression-list )if the postfix-expression denotes a set of overloaded functions and/or function templates, overload resolution is applied as specified in [over.call.func].
postfix-expression: postfix-expression . id-expression postfix-expression -> id-expression primary-expressionThese represent two syntactic subcategories of function calls: qualified function calls and unqualified function calls.
operator conversion-type-id ( ) cv-qualifier ref-qualifier noexcept-specifier attribute-specifier-seq ;where cv-qualifier 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 () returning R”, or the type “reference to pointer to function of () returning R”, or the type “reference to function of () returning R”, a surrogate call function with the unique name call-function and having the form
R call-function ( conversion-type-id F, P a, …, P a) { return F (a, …, a); }is also considered as a candidate function.
int f1(int);
int f2(float);
typedef int (*fp1)(int);
typedef int (*fp2)(float);
struct A {
operator fp1() { return f1; }
operator fp2() { return f2; }
} a;
int i = a(1); // calls f1 via pointer returned from conversion function