libcxx

libcxx mirror with random patches
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default.pass.cpp (3029B)

      1 //===----------------------------------------------------------------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is dual licensed under the MIT and the University of Illinois Open
      6 // Source Licenses. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 
     10 // <tuple>
     11 
     12 // template <class... Types> class tuple;
     13 
     14 // constexpr tuple();
     15 
     16 // UNSUPPORTED: c++98, c++03
     17 
     18 #include <tuple>
     19 #include <string>
     20 #include <cassert>
     21 #include <type_traits>
     22 
     23 #include "DefaultOnly.h"
     24 
     25 struct NoDefault {
     26     NoDefault() = delete;
     27     explicit NoDefault(int) { }
     28 };
     29 
     30 struct NoExceptDefault {
     31     NoExceptDefault() noexcept = default;
     32 };
     33 
     34 struct ThrowingDefault {
     35     ThrowingDefault() { }
     36 };
     37 
     38 struct IllFormedDefault {
     39     IllFormedDefault(int x) : value(x) {}
     40     template <bool Pred = false>
     41     constexpr IllFormedDefault() {
     42         static_assert(Pred,
     43             "The default constructor should not be instantiated");
     44     }
     45     int value;
     46 };
     47 
     48 int main()
     49 {
     50     {
     51         std::tuple<> t;
     52         (void)t;
     53     }
     54     {
     55         std::tuple<int> t;
     56         assert(std::get<0>(t) == 0);
     57     }
     58     {
     59         std::tuple<int, char*> t;
     60         assert(std::get<0>(t) == 0);
     61         assert(std::get<1>(t) == nullptr);
     62     }
     63     {
     64         std::tuple<int, char*, std::string> t;
     65         assert(std::get<0>(t) == 0);
     66         assert(std::get<1>(t) == nullptr);
     67         assert(std::get<2>(t) == "");
     68     }
     69     {
     70         std::tuple<int, char*, std::string, DefaultOnly> t;
     71         assert(std::get<0>(t) == 0);
     72         assert(std::get<1>(t) == nullptr);
     73         assert(std::get<2>(t) == "");
     74         assert(std::get<3>(t) == DefaultOnly());
     75     }
     76     {
     77         // See bug #21157.
     78         static_assert(!std::is_default_constructible<std::tuple<NoDefault>>(), "");
     79         static_assert(!std::is_default_constructible<std::tuple<DefaultOnly, NoDefault>>(), "");
     80         static_assert(!std::is_default_constructible<std::tuple<NoDefault, DefaultOnly, NoDefault>>(), "");
     81     }
     82     {
     83         static_assert(noexcept(std::tuple<NoExceptDefault>()), "");
     84         static_assert(noexcept(std::tuple<NoExceptDefault, NoExceptDefault>()), "");
     85 
     86         static_assert(!noexcept(std::tuple<ThrowingDefault, NoExceptDefault>()), "");
     87         static_assert(!noexcept(std::tuple<NoExceptDefault, ThrowingDefault>()), "");
     88         static_assert(!noexcept(std::tuple<ThrowingDefault, ThrowingDefault>()), "");
     89     }
     90     {
     91         constexpr std::tuple<> t;
     92         (void)t;
     93     }
     94     {
     95         constexpr std::tuple<int> t;
     96         assert(std::get<0>(t) == 0);
     97     }
     98     {
     99         constexpr std::tuple<int, char*> t;
    100         assert(std::get<0>(t) == 0);
    101         assert(std::get<1>(t) == nullptr);
    102     }
    103     {
    104     // Check that the SFINAE on the default constructor is not evaluated when
    105     // it isn't needed. If the default constructor is evaluated then this test
    106     // should fail to compile.
    107         IllFormedDefault v(0);
    108         std::tuple<IllFormedDefault> t(v);
    109     }
    110 }