[Bug c++/48449] New: [C++0x][SFINAE] Hard errors during value-initialization expressions

[daniel.kruegler at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48449

           Summary: [C++0x][SFINAE] Hard errors during
                    value-initialization expressions
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: daniel.kruegler@googlemail.com
                CC: jason@redhat.com


The following code involving reference types, function types, and abstract
class type should be well-formed, but are not:

template<class T, class = decltype(T())>
char f(int);

template<class>
char (&f(...))[2];

struct A { virtual ~A() = 0; };

static_assert(sizeof(f<int&>(0)) != 1, "Error"); // a
static_assert(sizeof(f<void()>(0)) != 1, "Error"); // b
static_assert(sizeof(f<A>(0)) != 1, "Error"); // c

The corresponding error messages are:

a) "error: invalid value-initialization of reference type"
b) "error: conversion from 'int' to non-scalar type 'void()' requested"
c) "error: cannot allocate an object of abstract type 'A' because the
following virtual functions are pure within 'A': virtual A::~A()"