add a separate Buffer class

1 files changed, 69 insertions, 0 deletions

diff --git a/include/winapi/buffer.hpp b/include/winapi/buffer.hpp
new file mode 100644
index 0000000..246822e
--- /dev/null
+++ b/include/winapi/buffer.hpp
@@ -0,0 +1,69 @@
+// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
+// This file is part of the "winapi-common" project.
+// For details, see https://github.com/egor-tensin/winapi-common.
+// Distributed under the MIT License.
+
+#pragma once
+
+#include <cstddef>
+#include <cstring>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <utility>
+#include <vector>
+
+namespace winapi {
+
+class Buffer : public std::vector<unsigned char> {
+public:
+    typedef std::vector<unsigned char> Parent;
+
+    Buffer() = default;
+
+    explicit Buffer(Parent&& src) : Parent(std::move(src)) {}
+
+    template <typename CharT>
+    explicit Buffer(const std::basic_string<CharT>& src) {
+        set(src);
+    }
+
+    explicit Buffer(const void* src, std::size_t nb) { set(src, nb); }
+
+    template <typename CharT>
+    void set(const std::basic_string<CharT>& src) {
+        set(src.c_str(), src.length() * sizeof(std::basic_string<CharT>::char_type));
+    }
+
+    void set(const void* src, std::size_t nb) {
+        resize(nb);
+        std::memcpy(data(), src, nb);
+    }
+
+    std::string as_utf8() const {
+        const auto c_str = reinterpret_cast<const char*>(data());
+        const auto nb = size();
+        const auto nch = nb;
+        return {c_str, nch};
+    }
+
+    std::wstring as_utf16() const {
+        const auto c_str = reinterpret_cast<const wchar_t*>(data());
+        const auto nb = size();
+        if (nb % 2 != 0) {
+            std::ostringstream oss;
+            oss << "Buffer size invalid at " << nb << " bytes";
+            throw std::runtime_error{oss.str()};
+        }
+        const auto nch = nb / 2;
+        return {c_str, nch};
+    }
+
+    void add(const Buffer& src) {
+        const auto nb = size();
+        resize(size() + src.size());
+        std::memcpy(data() + nb, src.data(), src.size());
+    }
+};
+
+} // namespace winapi