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// based on test-wrapper.cpp
 
#include <iostream>
#include <string>
 
template <typename T> class foo {
public:
	T id;
	void setId(T iniName) {
		id = iniName;
	}
};
 
template <typename T> struct foowrapper {
	foo<T> const & objFoowrapper;
};
 
template <typename T> foowrapper<T> print(foo<T> const & objprint) {
	return {objprint}; // without curly brackets: error: conversion from ‘const foo’ to non-scalar type ‘foowrapper’ requested
}
 
template <typename T> std::ostream & operator<<(std::ostream & lhs, foowrapper<T> const & rhs) {
	lhs << '[' << rhs.objFoowrapper.id << ']';
}
 
int main() {
	foo<std::string> f;
	f.setId("blah");
	std::cout << print(f) << std::endl;
 
	foo<int> g;
	g.setId(147);
	std::cout << print(g) << std::endl;
	g.id *= 2;
	std::cout << print(g) << std::endl;
}
 

prog.cpp: In function ‘foowrapper<T> print(const foo<T>&)’:
prog.cpp:19: error: expected primary-expression before ‘{’ token
prog.cpp:19: error: expected ‘;’ before ‘{’ token
prog.cpp:19: error: expected `;' before ‘}’ token
prog.cpp: In function ‘std::ostream& operator<<(std::ostream&, const foowrapper<T>&)’:
prog.cpp:24: warning: no return statement in function returning non-void
prog.cpp: In function ‘foowrapper<T> print(const foo<T>&) [with T = std::basic_string<char, std::char_traits<char>, std::allocator<char> >]’:
prog.cpp:29:   instantiated from here
prog.cpp:19: warning: statement has no effect
prog.cpp: In function ‘foowrapper<T> print(const foo<T>&) [with T = int]’:
prog.cpp:33:   instantiated from here
prog.cpp:19: warning: statement has no effect

Standard output is empty