54 lines
2.7 KiB
C++
54 lines
2.7 KiB
C++
// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
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// RUN: %clang_cc1 -fsyntax-only -verify -std=c++2a %s
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// A constexpr specifier used in an object declaration declares the object as
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// const.
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constexpr int a = 0;
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extern const int a;
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int i; // expected-note 2{{here}}
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constexpr int *b = &i;
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extern int *const b;
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constexpr int &c = i;
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extern int &c;
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constexpr int (*d)(int) = 0;
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extern int (*const d)(int);
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// A variable declaration which uses the constexpr specifier shall have an
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// initializer and shall be initialized by a constant expression.
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constexpr int ni1; // expected-error {{default initialization of an object of const type 'const int'}}
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constexpr struct C { C(); } ni2; // expected-error {{cannot have non-literal type 'const struct C'}} expected-note 3{{has no constexpr constructors}}
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constexpr double &ni3; // expected-error {{declaration of reference variable 'ni3' requires an initializer}}
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constexpr int nc1 = i; // expected-error {{constexpr variable 'nc1' must be initialized by a constant expression}} expected-note {{read of non-const variable 'i' is not allowed in a constant expression}}
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constexpr C nc2 = C(); // expected-error {{cannot have non-literal type 'const C'}}
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int &f(); // expected-note 2{{declared here}}
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constexpr int &nc3 = f(); // expected-error {{constexpr variable 'nc3' must be initialized by a constant expression}} expected-note {{non-constexpr function 'f' cannot be used in a constant expression}}
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constexpr int nc4(i); // expected-error {{constexpr variable 'nc4' must be initialized by a constant expression}} expected-note {{read of non-const variable 'i' is not allowed in a constant expression}}
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constexpr C nc5((C())); // expected-error {{cannot have non-literal type 'const C'}}
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constexpr int &nc6(f()); // expected-error {{constexpr variable 'nc6' must be initialized by a constant expression}} expected-note {{non-constexpr function 'f'}}
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struct pixel {
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int x, y;
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};
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constexpr pixel ur = { 1294, 1024 }; // ok
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constexpr pixel origin; // expected-error {{default initialization of an object of const type 'const pixel' without a user-provided default constructor}}
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#if __cplusplus > 201702L
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// A constexpr variable shall have constant destruction.
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struct A {
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bool ok;
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constexpr A(bool ok) : ok(ok) {}
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constexpr ~A() noexcept(false) {
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void oops(); // expected-note 2{{declared here}}
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if (!ok) oops(); // expected-note 2{{non-constexpr function}}
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}
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};
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constexpr A const_dtor(true);
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constexpr A non_const_dtor(false); // expected-error {{must have constant destruction}} expected-note {{in call}}
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constexpr A arr_dtor[5] = {true, true, true, false, true}; // expected-error {{must have constant destruction}} expected-note {{in call to '&arr_dtor[3]->~A()'}}
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#endif
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