1 files changed, 149 insertions, 0 deletions
diff --git a/src/toml11/toml/utility.hpp b/src/toml11/toml/utility.hpp
new file mode 100644
index 000000000..4a6b4309d
--- /dev/null
+++ b/src/toml11/toml/utility.hpp
@@ -0,0 +1,149 @@
+//     Copyright Toru Niina 2017.
+// Distributed under the MIT License.
+#ifndef TOML11_UTILITY_HPP
+#define TOML11_UTILITY_HPP
+#include <memory>
+#include <sstream>
+#include <utility>
+
+#include "traits.hpp"
+
+#if __cplusplus >= 201402L
+#  define TOML11_MARK_AS_DEPRECATED(msg) [[deprecated(msg)]]
+#elif defined(__GNUC__)
+#  define TOML11_MARK_AS_DEPRECATED(msg) __attribute__((deprecated(msg)))
+#elif defined(_MSC_VER)
+#  define TOML11_MARK_AS_DEPRECATED(msg) __declspec(deprecated(msg))
+#else
+#  define TOML11_MARK_AS_DEPRECATED
+#endif
+
+namespace toml
+{
+
+#if __cplusplus >= 201402L
+
+using std::make_unique;
+
+#else
+
+template<typename T, typename ... Ts>
+inline std::unique_ptr<T> make_unique(Ts&& ... args)
+{
+    return std::unique_ptr<T>(new T(std::forward<Ts>(args)...));
+}
+
+#endif // __cplusplus >= 2014
+
+namespace detail
+{
+template<typename Container>
+void try_reserve_impl(Container& container, std::size_t N, std::true_type)
+{
+    container.reserve(N);
+    return;
+}
+template<typename Container>
+void try_reserve_impl(Container&, std::size_t, std::false_type) noexcept
+{
+    return;
+}
+} // detail
+
+template<typename Container>
+void try_reserve(Container& container, std::size_t N)
+{
+    if(N <= container.size()) {return;}
+    detail::try_reserve_impl(container, N, detail::has_reserve_method<Container>{});
+    return;
+}
+
+namespace detail
+{
+inline std::string concat_to_string_impl(std::ostringstream& oss)
+{
+    return oss.str();
+}
+template<typename T, typename ... Ts>
+std::string concat_to_string_impl(std::ostringstream& oss, T&& head, Ts&& ... tail)
+{
+    oss << std::forward<T>(head);
+    return concat_to_string_impl(oss, std::forward<Ts>(tail) ... );
+}
+} // detail
+
+template<typename ... Ts>
+std::string concat_to_string(Ts&& ... args)
+{
+    std::ostringstream oss;
+    oss << std::boolalpha << std::fixed;
+    return detail::concat_to_string_impl(oss, std::forward<Ts>(args) ...);
+}
+
+template<typename T>
+T from_string(const std::string& str, T opt)
+{
+    T v(opt);
+    std::istringstream iss(str);
+    iss >> v;
+    return v;
+}
+
+namespace detail
+{
+#if __cplusplus >= 201402L
+template<typename T>
+decltype(auto) last_one(T&& tail) noexcept
+{
+    return std::forward<T>(tail);
+}
+
+template<typename T, typename ... Ts>
+decltype(auto) last_one(T&& /*head*/, Ts&& ... tail) noexcept
+{
+    return last_one(std::forward<Ts>(tail)...);
+}
+#else // C++11
+// The following code
+// ```cpp
+//  1 | template<typename T, typename ... Ts>
+//  2 | auto last_one(T&& /*head*/, Ts&& ... tail)
+//  3 |  -> decltype(last_one(std::forward<Ts>(tail)...))
+//  4 | {
+//  5 |     return last_one(std::forward<Ts>(tail)...);
+//  6 | }
+// ```
+// does not work because the function `last_one(...)` is not yet defined at
+// line #3, so `decltype()` cannot deduce the type returned from `last_one`.
+// So we need to determine return type in a different way, like a meta func.
+
+template<typename T, typename ... Ts>
+struct last_one_in_pack
+{
+    using type = typename last_one_in_pack<Ts...>::type;
+};
+template<typename T>
+struct last_one_in_pack<T>
+{
+    using type = T;
+};
+template<typename ... Ts>
+using last_one_in_pack_t = typename last_one_in_pack<Ts...>::type;
+
+template<typename T>
+T&& last_one(T&& tail) noexcept
+{
+    return std::forward<T>(tail);
+}
+template<typename T, typename ... Ts>
+enable_if_t<(sizeof...(Ts) > 0), last_one_in_pack_t<Ts&& ...>>
+last_one(T&& /*head*/, Ts&& ... tail)
+{
+    return last_one(std::forward<Ts>(tail)...);
+}
+
+#endif
+} // detail
+
+}// toml
+#endif // TOML11_UTILITY