原始内容
高亮显示
复制内容
// RUN: %clang_cc1 -fsyntax-only -fcxx-exceptions -verify -std=c++11 -Wall %s template<bool b> struct ExceptionIf { static int f(); }; template<> struct ExceptionIf<false> { typedef int f; }; // The exception specification of a defaulted default constructor depends on // the contents of in-class member initializers. However, the in-class member // initializers can depend on the exception specification of the constructor, // since the class is considered complete within them. We reject any such cases. namespace InClassInitializers { // Noexcept::Noexcept() is implicitly declared as noexcept(false), because it // directly invokes ThrowSomething(). However... // // If noexcept(Noexcept()) is false, then Noexcept() is a constant expression, // so noexcept(Noexcept()) is true. But if noexcept(Noexcept()) is true, then // Noexcept::Noexcept is not declared constexpr, therefore noexcept(Noexcept()) // is false. bool ThrowSomething() noexcept(false); struct ConstExpr { bool b = noexcept(ConstExpr()) && ThrowSomething(); // expected-error {{exception specification is not available until end of class definition}} }; // We can use it now. bool w = noexcept(ConstExpr()); // Much more obviously broken: we can't parse the initializer without already // knowing whether it produces a noexcept expression. struct TemplateArg { int n = ExceptionIf<noexcept(TemplateArg())>::f(); // expected-error {{exception specification is not available until end of class definition}} }; bool x = noexcept(TemplateArg()); // And within a nested class. struct Nested { struct Inner { int n = ExceptionIf<noexcept(Nested())>::f(); // expected-error {{exception specification is not available until end of class definition}} } inner; }; bool y = noexcept(Nested()); bool z = noexcept(Nested::Inner()); } namespace ExceptionSpecification { struct Nested { struct T { T() noexcept(!noexcept(Nested())); // expected-error{{exception specification is not available until end of class definition}} } t; }; } namespace DefaultArgument { struct Default { struct T { T(int = ExceptionIf<noexcept(Default())::f()); // expected-error {{call to implicitly-deleted default constructor}} } t; // expected-note {{has no default constructor}} }; }
您还没有登录,登录后您可以:
首次使用?从这里 注册