How to make a template specialization for trivial types using is_trivial? At the same time, pointers are also trivial, but a separate specialization should remain for them. i am using c++11.
#include <string>
#include <iostream>
#include <type_traits>
#include <vector>
#define Work(var) A<decltype(var)>().print(&var);
//Base class
class ABase{
public:
virtual void print(void* ptr)=0;
};
//default template
template <class T>
class A : public ABase{
public:
void print(void* ptr) override {
std::cout<<"default "<<ptr<<" size:"<<sizeof(T)<<std::endl;
}
};
// template for pointers
template <class T>
class A<T*> : public ABase{
public:
void print(void* ptr) override {
std::cout<<"pointer "<<ptr<<" content:"<<std::endl;
T* val=static_cast<T*>(ptr);
Work(*val);
}
};
// template for arrays
template <class T, std::size_t N>
class A<T[N]> : public ABase{
public:
void print(void* ptr) override {
std::cout<<"array "<<ptr<<" size:"<<sizeof(T[N])<<" count:"<<N<<std::endl;
}
};
// template for is_trivial HOW?
template <>
class A<int>: public ABase{ // MUST BE FOR ALL TYPES using std::is_trivial<T>::value
typedef int T;
public:
void print(void* ptr) override {
char* d= static_cast<char*>(ptr);
std::cout<<"trivial "<<ptr<<" size:"<<sizeof(T)<<" dump:";
for(int i=0; i<sizeof(T); i++)
std::cout<<std::hex<<d[i];
std::cout<<std::endl;
}
};
int main(){
int x=10;
Work(x);
char c[5]="qwe";
Work(c);
char* str= &c[1];
Work(str);
}
I saw how this is done for functions, but there was a template data type in the function header and it simplified everything
Since you want C++11 specific solution, you can use std::is_fundamental, std::enable_if as shown below. Note that a second type parameter with a default has been added into the primary template for this to work:
//-----------------vvvvvvvvvvvvvvvv--------->added second parameter with default
template <class T, typename = void>
class A : public ABase{
public:
void print(void* ptr) override {
std::cout<<"default "<<ptr<<" size:"<<sizeof(T)<<std::endl;
}
};
//specialization for fundamental types
template <typename C>
class A<C, typename std::enable_if<std::is_fundamental<C>::value>::type>: public ABase{
};