template type that takes multiple args of any type, C++ (gcc)

template type that takes multiple args of any type

Language: Layout:

//g++  7.4.0

#include <vector>
#include <map>
#include <functional>
#include <iostream>

class tester1
{
public:
	void process(int a)
	{
		std::cout << a << std::endl;
	};
};

class tester2
{
public:
	void process(int a, int b)
	{
		std::cout << a << " " << b << std::endl;
	};
};

class tester3
{
public:
	void process(int a, int b, int c)
	{
		std::cout << a << " " << b << " " << c << std::endl;
	};
};

class tester4
{
public:
	void process(int a)
	{
		std::cout << a << std::endl;
	};
};

class tester5
{
public:
	void process(int a)
	{
		std::cout << a << std::endl;
	};
};

// The template type
template<typename... Args>
class tester_template
{
public:
	void process(Args... args)
	{
		// Create a vector to put the args into. use double since that can hold all of the types
		// that I am using
		std::vector<double> args_vect = {args...};
		for (auto arg : args_vect)
		{
			std::cout << arg << " ";
		}
		std::cout << std::endl;
	};
};

int main() {
	// Multiple classes for different param lists
	tester1 t1;
	tester2 t2;
	tester3 t3;
	tester4 t4;
	tester5 t5;
	
	t1.process(1);
	t2.process(2, 2);
	t3.process(3, 2, 3);
	t4.process(4);
	t5.process(5);

// Same with one template class
	tester_template<double> template1;
	tester_template<int, int> template2;
	tester_template<int, int, int> template3;
	tester_template<float> template4;
	tester_template<float, double, int> template5;
	
	template1.process(1.123);           // ok
	template2.process(2, 2);            // Warnings
	template3.process(3, 2, 3);         // Warnings
	template4.process(4.4f);            // Warnings 
	template5.process(5.5f, 2.234, 3);  // Warnings
	
    return 0;
}

Show compiler warnings [ + ] Compiler args [ + ] Show input
Compilation time: 0.66 sec, absolute running time: 0.05 sec, cpu time: 0 sec, memory peak: 3 Mb, absolute service time: 0,79 sec

edit mode | history

Warning(s):

725307824/source.cpp: In instantiation of ‘void tester_template<Args>::process(Args ...) [with Args = {int, int}]’:
725307824/source.cpp:95:24:   required from here
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#0’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
   std::vector<double> args_vect = {args...};
                       ^~~~~~~~~
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#0’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#1’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#1’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp: In instantiation of ‘void tester_template<Args>::process(Args ...) [with Args = {int, int, int}]’:
725307824/source.cpp:96:27:   required from here
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#0’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#0’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#1’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#1’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#2’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#2’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp: In instantiation of ‘void tester_template<Args>::process(Args ...) [with Args = {float, double, int}]’:
725307824/source.cpp:98:34:   required from here
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#2’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]
725307824/source.cpp:64:23: warning: narrowing conversion of ‘args#2’ from ‘int’ to ‘double’ inside { } [-Wnarrowing]

1
2 2
3 2 3
4
5
1.123 
2 2 
3 2 3 
4.4 
5.5 2.234 3

λ

                                      .NET NoSQL database for rapid development