我需要在C++编写一个模板函数replace_all
这将需要一个字符串,wstring的,glibmm :: ustring等并用replace
取代的search
所有出现在subject
。未定义参考函数模板
replace_all.cc
template < class T >
T replace_all(
T const &search,
T const &replace,
T const &subject
) {
T result;
typename T::size_type done = 0;
typename T::size_type pos;
while ((pos = subject.find(search, done)) != T::npos) {
result.append (subject, done, pos - done);
result.append (replace);
done = pos + search.size();
}
result.append(subject, done, subject.max_size());
return result;
}
test.cc
#include <iostream>
template < class T >
T replace_all(
T const &search,
T const &replace,
T const &subject
);
// #include "replace_all.cc"
using namespace std;
int main()
{
string const a = "foo bar fee boor foo barfoo b";
cout << replace_all<string>("foo", "damn", a) << endl;
return 0;
}
当我尝试编译此使用gcc 4.1.2
g++ -W -Wall -c replace_all.cc
g++ -W -Wall -c test.cc
g++ test.o replace_all.o
我得到:
test.o: In function `main':
test.cc:(.text+0x13b): undefined reference to `
std::basic_string<char, std::char_traits<char>, std::allocator<char> >
replace_all< std::basic_string<char, std::char_traits<char>, std::allocator<char> > >(
std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&,
std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&,
std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&
)
'
collect2: ld returned 1 exit status
但是,当我取消在test.cc #include "replace_all.cc"
和编译这样:
g++ -W -Wall test.cc
程序的链接并产生预期的输出:
damn bar fee boor damn bardamn b
为什么连接失败,我能做些什么,使工作?