Re: Universal function for basic_string processing
alexei.alexandrov@gmail.com schrieb:
template <typename T>
bool beginsWith(const std::basic_string<T>& str, const
std::basic_string<T>& prefix)
{
if (str.size() < prefix.size())
{
return false;
}
return std::equal(prefix.begin(), prefix.end(), str.begin());
}
but it doesn't work for
std::string str = "123";
bool matches = beginsWith(str, "1");
since template type matching doesn't seem to check for type conversion
possibility. Only explicit
std::string str = "123";
bool matches = beginsWith(str, std::string("1"));
would work.
You have to supress the exact matching attempt of the second argument.
Use this approach:
template <typename T>
struct Identity
{
typedef T Type;
};
template <typename T>
bool beginsWith(const std::basic_string<T>& str, const
typename Identity<std::basic_string<T> >::Type& prefix)
{
if (str.size() < prefix.size())
{
return false;
}
return std::equal(prefix.begin(), prefix.end(), str.begin());
}
Greetings from Bremen,
Daniel Kr|gler
--
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