Please take note of the updates at the end of this post.
Update: I have created a public project on GitHub for this library!
I would like to have a single template that once and for all takes care of pretty-printing all STL containers via operator<<. In pseudo code, I'm looking for something like this:
template<container C, class T, String delim = ", ", String open = "[", String close = "]">
std::ostream & operator<<(std::ostream & o, const C<T> …我想编写一个模板来确定类型是否是编译时的stl容器.
我有以下一点代码:
struct is_cont{};
struct not_cont{};
template <typename T>
struct is_cont { typedef not_cont result_t; };
但我不确定如何创建必要的专业化std::vector<T,Alloc>, deque<T,Alloc>, set<T,Alloc,Comp>等...
我想知道是否有可能拥有具有以下行为的代码:
int main()
{
func<vector>(/*some arguments*/);
}
也就是说,我希望用户能够指定容器而不指定其操作的类型.
例如,可能定义的某些(元)代码(不适用于上述代码)func将如下所示:
template<typename ContainerType>
int func(/*some parameters*/)
{
ContainerType<int> some_container;
/*
operate on some_container here
*/
return find_value(some_container);
}
我想通过操作符<<调用一次外部集合来输出集合的集合（在这种情况下为向量的向量）
当我' '从operator<<()函数中删除the时，它可以工作，但是我希望每行的每个输出元素之间都有一个空格。我尝试用（也包括字符串头文件）替换' '，" "但得到相同的错误。
有办法解决吗？
#include <iostream>
#include <vector>
using namespace std;
vector<vector<bool>> lookup(10, vector<bool>(10, true));
template <typename T>
ostream& operator<< (ostream& out, const T& collection)
{
for (const auto& elem : collection)
out << elem << ' ';
return out << endl;
}
int main()
{
cout << lookup << endl;
}
我收到以下错误：
1>------ Build started: Project: test, Configuration: Debug Win32 ------
1>test.cpp
1>c:\users\user\source\repos\codechef\practice\beginner\test\test\test.cpp(16): error C2593: 'operator <<' is ambiguous …