common: Add CString wrapper to handle native null-terminated strings

CMakeLists.txt

@@ -349,6 +349,7 @@ set(COMMON src/common/logging/backend.cpp
            src/common/concepts.h
            src/common/config.cpp
            src/common/config.h
+           src/common/cstring.h
            src/common/debug.h
            src/common/disassembler.cpp
            src/common/disassembler.h

src/common/cstring.h

@@ -0,0 +1,119 @@
+// SPDX-FileCopyrightText: Copyright 2024 shadPS4 Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <string_view>
+
+#include "assert.h"
+
+namespace Common {
+
+/**
+ * @brief A null-terminated string with a fixed maximum length
+ *        This class is not meant to be used as a general-purpose string class
+ *        It is meant to be used as `char[N]` where memory layout is fixed
+ * @tparam N Maximum length of the string
+ * @tparam T Type of character
+ */
+template <size_t N, typename T = char>
+class CString {
+public:
+    class Iterator;
+
+    T data[N]{};
+
+public:
+    CString() = default;
+
+    template <size_t M>
+    explicit CString(const CString<M>& other)
+        requires(M <= N)
+    {
+        std::ranges::copy(other.begin(), other.end(), data);
+    }
+
+    void FromString(const std::basic_string_view<T>& str) {
+        size_t p = str.copy(data, N - 1);
+        data[p] = '\0';
+    }
+
+    void Zero() {
+        std::ranges::fill(data, 0);
+    }
+
+    explicit(false) operator std::basic_string_view<T>() const {
+        return std::basic_string_view<T>{data};
+    }
+
+    explicit operator std::basic_string<T>() const {
+        return std::basic_string<T>{data};
+    }
+
+    std::basic_string<T> to_string() const {
+        return std::basic_string<T>{data};
+    }
+
+    std::basic_string_view<T> to_view() const {
+        return std::basic_string_view<T>{data};
+    }
+
+    char* begin() {
+        return data;
+    }
+
+    const char* begin() const {
+        return data;
+    }
+
+    char* end() {
+        return data + N;
+    }
+
+    const char* end() const {
+        return data + N;
+    }
+
+    T& operator[](size_t idx) {
+        return data[idx];
+    }
+
+    const T& operator[](size_t idx) const {
+        return data[idx];
+    }
+
+    class Iterator {
+        T* ptr;
+        T* end;
+
+    public:
+        using difference_type = std::ptrdiff_t;
+        using value_type = T;
+        using pointer = T*;
+        using reference = T&;
+        using iterator_category = std::random_access_iterator_tag;
+
+        Iterator() = default;
+        explicit Iterator(T* ptr) : ptr(ptr), end(ptr + N) {}
+
+        Iterator& operator++() {
+            ++ptr;
+            return *this;
+        }
+
+        Iterator operator++(int) {
+            Iterator tmp = *this;
+            ++ptr;
+            return tmp;
+        }
+
+        operator T*() {
+            ASSERT_MSG(ptr >= end, "CString iterator out of bounds");
+            return ptr;
+        }
+    };
+};
+static_assert(sizeof(CString<13>) == sizeof(char[13])); // Ensure size still matches a simple array
+static_assert(std::weakly_incrementable<CString<13>::Iterator>);
+
+} // namespace Common