因此,在使用 std::array 时,我想要一种简单的方法来打印出数组的所有元素,并尝试了以下方法:
using namespace std;
template <class T, int N>
ostream& operator<<(ostream& o, const array<T, N>& arr)
{
copy(arr.cbegin(), arr.cend(), ostream_iterator<T>(o, " "));
return o;
}
int main()
{
array<int, 3> arr {1, 2, 3};
cout << arr;
}
但是,每当我尝试运行它时,我都会收到以下错误:
test.cpp: In function 'int main()':
test.cpp:21:10: error: cannot bind 'std::ostream {aka std::basic_ostream<char>}' lvalue to 'std::basic_ostream<char>&&'
c:\mingw\bin\../lib/gcc/mingw32/4.6.2/include/c++/ostream:581:5: error: initializing argument 1 of 'std::basic_ostream<_CharT, _Traits>& std::operator<<(std::basic_ostream<_CharT, _Traits>&&, const _Tp&) [with _CharT = char, _Traits = std::char_traits<char>, _Tp = std::array<int, 3u>]'
关于此错误的含义以及我将如何修复它有什么想法吗?
如果我将 operator<< 替换为 template<...> print_array(const array&) 之类的函数,错误会发生变化:
test.cpp: In function 'int main()':
test.cpp:20:17: error: no matching function for call to 'print_array(std::array<int, 3u>&)'
test.cpp:20:17: note: candidate is:
test.cpp:12:6: note: template<class T, int N> void print_array(const std::array<T, N>&)
最佳答案
使用std::size_t
帮助编译器推断类型:
template <class T, std::size_t N>
ostream& operator<<(ostream& o, const array<T, N>& arr)
{
copy(arr.cbegin(), arr.cend(), ostream_iterator<T>(o, " "));
return o;
}
关于c++ - 打印 std::array,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19152178/