to_string.hpp

@@ -18,15 +18,16 @@
 template<auto N, unsigned int base, typename char_type,
     std::enable_if_t<std::is_integral_v<decltype(N)>, int> = 0,
     std::enable_if_t<(base > 1 && base < 37), int> = 0>
-struct to_string_t {
+class to_string_t {
     // The lambda calculates what the string length of N will be, so that `buf`
     // fits to the number perfectly.
-    char_type buf[([] {
+    char_type buf[([]() constexpr noexcept {
                        unsigned int len = N > 0 ? 1 : 2;
                        for (auto n = N < 0 ? -N : N; n; len++, n /= base);
                        return len;
                    }())] = {};
 
+ public:
     /**
      * Constructs the object, filling `buf` with the string representation of N.
      */
@@ -44,14 +45,24 @@ struct to_string_t {
     }
 
     // Support implicit casting to `char *` or `const char *`.
-    constexpr operator char_type *() { return buf; }
+    constexpr operator char_type *() noexcept { return buf; }
-    constexpr operator const char_type *() const { return buf; }
+    constexpr operator const char_type *() const noexcept { return buf; }
-    
+
-    // Support range-based for loops
+    constexpr auto size() const noexcept { return sizeof(buf) / sizeof(buf[0]); }
-    constexpr auto begin() { return buf; }
+    // Element access
-    constexpr auto begin() const { return buf; }
+    constexpr auto data() noexcept { return buf; }
-    constexpr auto end() { return buf + sizeof(buf) / sizeof(buf[0]); }
+    constexpr auto data() const noexcept { return buf; }
-    constexpr auto end() const { return buf + sizeof(buf) / sizeof(buf[0]); }
+    constexpr auto operator[](unsigned int i) noexcept { return buf[i]; }
+    constexpr auto operator[](unsigned int i) const noexcept { return buf[i]; }
+    constexpr auto front() noexcept { return buf[0]; }
+    constexpr auto front() const noexcept { return buf[0]; }
+    constexpr auto back() noexcept { return buf[size() - 1]; }
+    constexpr auto back() const noexcept { return buf[size() - 1]; }
+    // Iterators
+    constexpr auto begin() noexcept { return buf; }
+    constexpr auto begin() const noexcept { return buf; }
+    constexpr auto end() noexcept { return buf + size(); }
+    constexpr auto end() const noexcept { return buf + size(); }
 };
 
 /**
@@ -59,5 +70,5 @@ struct to_string_t {
  */
 template<auto N, unsigned int base = 10, typename char_type = char>
 constexpr to_string_t<N, base, char_type> to_string;
- 
+
 #endif // TCSULLIVAN_TO_STRING_HPP_