util: Enhance Join()

This commit is contained in:
Hennadii Stepanov 2020-05-09 14:45:47 +03:00
parent fe05dd0611
commit 4c9b9a4882
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@ -30,10 +30,11 @@ NODISCARD inline std::string TrimString(const std::string& str, const std::strin
* @param separator The separator
* @param unary_op Apply this operator to each item in the list
*/
template <typename T, typename UnaryOp>
std::string Join(const std::vector<T>& list, const std::string& separator, UnaryOp unary_op)
template <typename T, typename BaseType, typename UnaryOp>
auto Join(const std::vector<T>& list, const BaseType& separator, UnaryOp unary_op)
-> decltype(unary_op(list.at(0)))
{
std::string ret;
decltype(unary_op(list.at(0))) ret;
for (size_t i = 0; i < list.size(); ++i) {
if (i > 0) ret += separator;
ret += unary_op(list.at(i));
@ -41,9 +42,16 @@ std::string Join(const std::vector<T>& list, const std::string& separator, Unary
return ret;
}
template <typename T>
T Join(const std::vector<T>& list, const T& separator)
{
return Join(list, separator, [](const T& i) { return i; });
}
// Explicit overload needed for c_str arguments, which would otherwise cause a substitution failure in the template above.
inline std::string Join(const std::vector<std::string>& list, const std::string& separator)
{
return Join(list, separator, [](const std::string& i) { return i; });
return Join<std::string>(list, separator);
}
/**