73 lines
3.6 KiB
C++
73 lines
3.6 KiB
C++
// RUN: %clang_cc1 -std=c++1z %s -verify
|
|
|
|
// The same restrictions apply to the parameter-declaration-clause of a
|
|
// deduction guide as in a function declaration.
|
|
template<typename T> struct A {};
|
|
A(void) -> A<int>; // expected-note {{previous}}
|
|
A(void, int) -> A<int>; // expected-error {{'void' must be the first and only parameter if specified}}
|
|
|
|
A() -> A<int>; // expected-error {{redeclaration of deduction guide}}
|
|
// expected-note@-1 {{previous}}
|
|
|
|
A() -> A<int>; // expected-note {{previous}}
|
|
// expected-error@-1 {{redeclaration of deduction guide}}
|
|
A() -> A<float>; // FIXME: "functions" is a poor term. expected-error {{functions that differ only in their return type cannot be overloaded}}
|
|
|
|
template<typename T> A(T) -> A<typename T::foo>;
|
|
template<typename T> A(T) -> A<typename T::bar>; // ok, can overload on return type (SFINAE applies)
|
|
|
|
A(long) -> A<int>;
|
|
template<typename T = int> A(long) -> A<char>; // ok, non-template beats template as usual
|
|
|
|
// (Pending DR) The template-name shall name a class template.
|
|
template<typename T> using B = A<T>; // expected-note {{template}}
|
|
B() -> B<int>; // expected-error {{cannot specify deduction guide for alias template 'B'}}
|
|
// FIXME: expected-error@-1 {{declarator requires an identifier}}
|
|
template<typename T> int C;
|
|
C() -> int; // expected-error {{requires a type specifier}}
|
|
template<typename T> void D();
|
|
D() -> int; // expected-error {{requires a type specifier}}
|
|
template<template<typename> typename TT> struct E { // expected-note 2{{template}}
|
|
// FIXME: Should only diagnose this once!
|
|
TT(int) -> TT<int>; // expected-error 2{{cannot specify deduction guide for template template parameter 'TT'}} expected-error {{requires an identifier}}
|
|
};
|
|
|
|
A(int) -> int; // expected-error {{deduced type 'int' of deduction guide is not a specialization of template 'A'}}
|
|
template<typename T> A(T) -> B<T>; // expected-error {{deduced type 'B<T>' (aka 'A<type-parameter-0-0>') of deduction guide is not written as a specialization of template 'A'}}
|
|
template<typename T> A(T*) -> const A<T>; // expected-error {{deduced type 'const A<T>' of deduction guide is not a specialization of template 'A'}}
|
|
|
|
// A deduction-guide shall be declared in the same scope as the corresponding
|
|
// class template.
|
|
namespace WrongScope {
|
|
namespace {
|
|
template<typename T> struct AnonNS1 {}; // expected-note {{here}}
|
|
AnonNS1(float) -> AnonNS1<float>; // ok
|
|
}
|
|
AnonNS1(int) -> AnonNS1<int>; // expected-error {{deduction guide must be declared in the same scope as template 'WrongScope::}}
|
|
template<typename T> struct AnonNS2 {}; // expected-note {{here}}
|
|
namespace {
|
|
AnonNS1(char) -> AnonNS1<char>; // ok
|
|
AnonNS2(int) -> AnonNS2<int>; // expected-error {{deduction guide must be declared in the same scope as template 'WrongScope::AnonNS2'}}
|
|
}
|
|
namespace N {
|
|
template<typename T> struct NamedNS1 {}; // expected-note {{here}}
|
|
template<typename T> struct NamedNS2 {}; // expected-note {{here}}
|
|
}
|
|
using N::NamedNS1;
|
|
NamedNS1(int) -> NamedNS1<int>; // expected-error {{deduction guide must be declared in the same scope as template}}
|
|
using namespace N;
|
|
NamedNS2(int) -> NamedNS2<int>; // expected-error {{deduction guide must be declared in the same scope as template}}
|
|
struct ClassMemberA {
|
|
template<typename T> struct X {}; // expected-note {{here}}
|
|
};
|
|
struct ClassMemberB : ClassMemberA {
|
|
X(int) -> X<int>; // expected-error {{deduction guide must be declared in the same scope as template 'WrongScope::ClassMemberA::X'}}
|
|
};
|
|
template<typename T> struct Local {};
|
|
void f() {
|
|
Local(int) -> Local<int>; // expected-error {{expected}}
|
|
using WrongScope::Local;
|
|
Local(int) -> Local<int>; // expected-error {{expected}}
|
|
}
|
|
}
|