optimize StartsWith,EndsWith

include/sled/apply.h

@@ -0,0 +1,58 @@
+#pragma once
+#ifndef SLED_APPLY_H
+#define SLED_APPLY_H
+#include <functional>
+#include <tuple>
+
+namespace sled {
+namespace detail {
+template<int... Seq>
+struct Sequence {};
+
+template<int N, int... Seq>
+struct MakeSeq : MakeSeq<N - 1, N - 1, Seq...> {};
+
+template<int... Seq>
+struct MakeSeq<0, Seq...> {
+    using type = Sequence<Seq...>;
+};
+
+template<typename ReturnT, typename Func, typename Tuple, int... Seq>
+ReturnT
+ApplyImpl(const Func &func, const Tuple &tuple, const Sequence<Seq...> &)
+{
+    return std::bind(func, std::get<Seq>(tuple)...)();
+}
+
+struct VoidTag {};
+
+}// namespace detail
+
+template<typename ReturnT,
+         typename Func,
+         typename Tuple,
+         typename std::enable_if<!std::is_void<ReturnT>::value, ReturnT>::type
+             * = nullptr>
+ReturnT
+apply(const Func &func, const Tuple &tuple)
+{
+    return detail::ApplyImpl<ReturnT>(
+        func, tuple,
+        typename detail::MakeSeq<std::tuple_size<Tuple>::value>::type());
+}
+
+template<typename ReturnT = void,
+         typename Func,
+         typename Tuple,
+         typename std::enable_if<std::is_void<ReturnT>::value,
+                                 detail::VoidTag>::type * = nullptr>
+void
+apply(const Func &func, const Tuple &tuple)
+{
+    detail::ApplyImpl<ReturnT>(
+        func, tuple,
+        typename detail::MakeSeq<std::tuple_size<Tuple>::value>::type());
+}
+
+}// namespace sled
+#endif// SLED_APPLY_H

src/strings/utils.cc

@@ -50,22 +50,15 @@ Trim(const std::string &str, const std::string &chars)
 std::string
 TrimLeft(const std::string &str, const std::string &chars)
 {
-    size_t start = 0;
+    size_t start = str.find_first_not_of(chars);
-    while (start < str.size()
+    return start == std::string::npos ? "" : str.substr(start);
-           && chars.find_first_of(str[start]) != std::string::npos) {
-        ++start;
-    }
-    return str.substr(start);
 }
 
 std::string
 TrimRight(const std::string &str, const std::string &chars)
 {
-    size_t end = str.size();
+    size_t end = str.find_last_not_of(chars);
-    while (end > 0 && chars.find_first_of(str[end - 1]) != std::string::npos) {
+    return end == std::string::npos ? "" : str.substr(0, end + 1);
-        --end;
-    }
-    return str.substr(0, end);
 }
 
 bool