Implemented something like a console (still WIP).

bastl/include/string

@@ -78,6 +78,15 @@ public:
     }
     constexpr basic_string& operator=(std::nullptr_t) = delete;
 
+    constexpr basic_string& operator+=(value_type chr) noexcept
+    {
+        return append(chr);
+    }
+    constexpr basic_string& operator+=(const basic_string& other) noexcept
+    {
+        return append(other);
+    }
+
     [[nodiscard]] constexpr reference operator[](size_type pos) noexcept { return _data[pos]; }
     [[nodiscard]] constexpr const_reference operator[](size_type pos) const noexcept { return _data[pos]; }
 
@@ -88,8 +97,8 @@ public:
     [[nodiscard]] constexpr reference front() noexcept { return _data.front(); }
     [[nodiscard]] constexpr const_reference front() const noexcept { return _data.front(); }
 
-    [[nodiscard]] constexpr reference back() noexcept { return _data.back(); }
-    [[nodiscard]] constexpr const_reference back() const noexcept { return _data.back(); }
+    [[nodiscard]] constexpr reference back() noexcept { return _data.at(size() - 1); }
+    [[nodiscard]] constexpr const_reference back() const noexcept { return _data.at(size() - 1); }
 
     [[nodiscard]] constexpr pointer data() noexcept { return _data.data(); }
     [[nodiscard]] constexpr const_pointer data() const noexcept { return _data.data(); }
@@ -117,6 +126,29 @@ public:
         _data.back() = value_type(0);
     }
 
+    constexpr basic_string& append(value_type chr) noexcept
+    {
+        _data.back() = chr;
+        _data.push_back(value_type());
+        return *this;
+    }
+    constexpr basic_string& append(const basic_string& other) noexcept
+    {
+        _data.reserve(_data.size() + other.size());
+        _data.resize(_data.size() - 1);
+        for (char chr : other)
+        {
+            _data.push_back(chr);
+        }
+        _data.push_back(value_type());
+        return *this;
+    }
+    constexpr void pop_back() noexcept
+    {
+        _data.pop_back();
+        _data.back() = value_type();
+    }
+
     static inline size_type npos = size_type(-1);
 };
 using string = basic_string<char>;