template template parameter

测试代码

C++ 11里面

#include <stdexcept>
#include <iostream>
#include <memory>
#include <vector>
#include <string>
#include <deque>

template<typename T>
using Vec = std::vector<T, std::allocator<T>>;

class A
{
private:
    int a = 0;
    int b = 2;
public:
    A() = default;
    A(int pa1, int pa2) :a(pa1), b(pa2) { printf("A Construct call!"); };
};

template<typename T,template<class> class Container>
class XCls
{
private:
    Container<T> elem;
public:
    XCls() {
        for (int i = 0; i < 4096; i++)
            elem.insert(elem.end(), T(i,4096-i));
    }
};

int main()
{
    XCls<A, Vec> test1;
}

 

在C++ 14里面这样已经不会报错了

#include <stdexcept>
#include <iostream>
#include <memory>
#include <vector>
#include <string>
#include <deque>

class A
{
private:
    int a = 0;
    int b = 2;
public:
    A() = default;
    A(int pa1, int pa2) :a(pa1), b(pa2) { printf("A Construct call!"); };
};

template<typename T,template<class> class Container>
class XCls
{
private:
    Container<T> elem;
public:
    XCls() {
        for (int i = 0; i < 4096; i++)
            elem.insert(elem.end(), T(i,4096-i));
    }
};

int main()
{
    XCls<A, std::vector> test1;
}

示例结果