Feature/regular expression metafunction

include/cpp2util.h

@@ -282,6 +282,7 @@
     #define CPP2_CONSTEXPR constexpr
 #endif
 
+#include "string_util.h"
 
 namespace cpp2 {
 
@@ -1977,6 +1978,7 @@ inline constexpr auto as_() -> decltype(auto)
 
 }
 
+#include "../source/regex.h"
 
 using cpp2::cpp2_new;
 

include/string_util.h

@@ -0,0 +1,67 @@
+#pragma once
+
+#include <string>
+#include <algorithm>
+
+// From https://stackoverflow.com/questions/216823/how-to-trim-a-stdstring
+
+// trim from start (in place)
+static inline void ltrim(std::string &s) {
+    s.erase(s.begin(), std::find_if(s.begin(), s.end(), [](unsigned char ch) {
+        return !std::isspace(ch);
+    }));
+}
+
+// trim from end (in place)
+static inline void rtrim(std::string &s) {
+    s.erase(std::find_if(s.rbegin(), s.rend(), [](unsigned char ch) {
+        return !std::isspace(ch);
+    }).base(), s.end());
+}
+
+// trim from both ends (in place)
+static inline void trim(std::string &s) {
+    rtrim(s);
+    ltrim(s);
+}
+
+// trim from start (copying)
+static inline std::string ltrim_copy(std::string_view s) {
+    std::string t(s);
+    ltrim(t);
+    return t;
+}
+
+// trim from end (copying)
+static inline std::string rtrim_copy(std::string_view s) {
+    std::string t(s);
+    rtrim(t);
+    return t;
+}
+
+// trim from both ends (copying)
+static inline std::string trim_copy(std::string_view s) {
+    std::string t(s);
+    trim(t);
+    return t;
+}
+
+// From https://oleksandrkvl.github.io/2021/04/02/cpp-20-overview.html#nttp
+
+template<typename CharT, std::size_t N>
+struct fixed_string {
+    constexpr fixed_string(const CharT (&s)[N+1]) {
+        std::copy_n(s, N + 1, str);
+    }
+    constexpr const CharT* data() const {
+        return str;
+    }
+    constexpr std::size_t size() const {
+        return N;
+    }
+
+    CharT str[N+1];
+};
+
+template<typename CharT, std::size_t N>
+fixed_string(const CharT (&)[N])->fixed_string<CharT, N-1>;