35 lines
1.3 KiB
C++
35 lines
1.3 KiB
C++
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// RUN: %clang_cc1 -std=c++2a -verify %s
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// When forming and checking satisfaction of atomic constraints, we will
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// substitute still-dependent template arguments into an expression, and later
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// substitute into the result. This creates some unique situations; check that
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// they work.
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namespace SubstIntoResolvedTypeTemplateArg {
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template<int, class> struct X {};
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template<class T> concept A = true;
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template<class T> concept B = sizeof(T) != 0;
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template<class T> concept C = B<X<1, T>>;
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int f(A auto); // expected-note {{candidate}}
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int f(C auto); // expected-note {{candidate}}
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int k1 = f(0); // expected-error {{ambiguous}}
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template<class T> concept D = A<T> && B<X<1, T>>;
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int f(D auto);
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int k2 = f(0); // ok
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// The atomic constraint formed from B<X<(int)'\1', T>> is identical to the
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// one formed from C, even though the template arguments are written as
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// different expressions; the "equivalent" rules are used rather than the
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// "identical" rules when matching template arguments in concept-ids.
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template<class T> concept E = A<T> && B<X<(int)'\1', T>>;
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int g(C auto);
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int g(E auto); // expected-note {{candidate}}
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int k3 = g(0);
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int g(D auto); // expected-note {{candidate}}
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int k4 = g(0); // expected-error {{ambiguous}}
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}
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