Merge pull request 'feature/no_std_lib' (#9) from feature/no_std_lib into master

Reviewed-on: http://git.mercurial-manifold.eu/an.tsouchlos/const_fmt/pulls/9

const_fmt/stdlib.h

@@ -187,8 +187,10 @@ concept floating_point = is_floating_point_v<type_t>;
 
 
 template <typename input_t, typename output_t>
-constexpr inline void copy(input_t* start, input_t* end, output_t* dest_start) {
+constexpr inline void copy(const input_t* start, const input_t* end, output_t* dest_start) {
-    memcpy(start, dest_start, end - start);
+    auto temp = start;
+    while (temp != end)
+        *(dest_start++) = *(temp++);
 }
 
 
@@ -235,13 +237,10 @@ public:
     }
 
     constexpr array() noexcept = default;
-
+    constexpr array(const array&) = default;
-    constexpr array(array&) = default;
-
     constexpr array(array&&) = default;
 
-    constexpr array& operator=(array& other) = default;
+    constexpr array& operator=(const array& other) = default;
-
     constexpr array& operator=(array&& other) = default;
 
     constexpr void swap(array<data_t, t_size>& other) noexcept {
@@ -272,6 +271,14 @@ public:
         return (&(m_data[t_size - 1]) + 1);
     }
 
+    constexpr const_iterator begin() const noexcept {
+        return &(m_data[0]);
+    }
+
+    constexpr const_iterator end() const noexcept {
+        return (&(m_data[t_size - 1]) + 1);
+    }
+
     constexpr const_iterator cbegin() const noexcept {
         return &(m_data[0]);
     }