make

g++ -g -Wall -c ui.cpp
ui.cpp: In function ‘T ui::in(std::string)’:
ui.cpp:13: error: ‘numeric_limits’ is not a member of ‘std’
ui.cpp:13: error: expected primary-expression before ‘>’ token
ui.cpp:13: error: ‘::max’ has not been declared
make: *** [ui.o] Fehler 1

makefile

CC    = g++
CPPFLAGS = -g -Wall

OBJECTS = ui.o

ifeq ($(shell uname -p | grep -o "64"),64)
	ARCH=64
else
	ARCH=32
endif

all: ui.exe

%.exe: ${OBJECTS}
	${CXX} ${LDFLAGS} -o $@ ${OBJECTS}

%.o: %.cpp %.h
	${CXX} ${CPPFLAGS} -c $<

.PHONY : clean
clean : 
	rm -f *.exe ${OBJECTS}

ui.cpp

#include "ui.h"

template <typename T>
T ui::in(std::string message){
	T read;
	while(true){
		std::cout << message << "\n";
		std::cin >> read;
		if(std::cin.good())return read;
		else{
			std::cout << "sorry, I did not understand\n";
			std::cin.clear();
			std::cin.ignore(std::numeric_limits<std::streamsize>::max(), '\n');
		}
	}
}

int main(){
	int foo = ui::in<int>("hallo");
	std::cout << foo << "\n";
}

ui.h

#pragma once

#include <limits>
#include <iostream>

namespace ui{
	template <typename T>
	T in(std::string message);
};