feat: embed

Author: vinniefalco

include/boost/capy/embed.hpp

@@ -0,0 +1,107 @@
+//
+// Copyright (c) 2025 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// Official repository: https://github.com/cppalliance/capy
+//
+
+#ifndef BOOST_CAPY_EMBED_HPP
+#define BOOST_CAPY_EMBED_HPP
+
+#include <boost/capy/detail/config.hpp>
+#include <boost/core/detail/string_view.hpp>
+
+#if __cpp_lib_string_view >= 201606L
+# include <string_view>
+#endif
+
+namespace boost {
+namespace capy {
+
+/** Embed a string literal as a string_view
+    
+    The embed class template is used to embed a string literal
+    in source code as a string_view. The first character of
+    the string literal will be removed, typically this is a
+    newline, allowing the string to be formatted nicely in code.
+
+    @par Example
+    @code
+    embed text(R"(
+    Hello "world"
+    This has quotes and )
+    )");
+    core::string_view sv = text.get();
+    @endcode
+    The resulting string_view `sv` will contain:
+    ```
+    Hello "world"
+    This has quotes and )
+    ```
+*/
+struct embed
+{
+    /** Constructor
+        The string literal `s` should be a raw string literal.
+        The first character (typically a newline) will be
+        removed from the resulting string_view.
+        @param s The string literal
+    */
+    template<std::size_t N>
+    constexpr
+    embed(
+        const char (&s)[N]) noexcept
+        : s_(s + 1, N - 2)
+    {
+    }
+
+    /** Conversion to string_view
+    */
+    operator core::string_view() const noexcept
+    {
+        return s_;
+    }
+
+#if __cpp_lib_string_view >= 201606L
+    /** Conversion to std::string_view
+    */
+    operator std::string_view() const noexcept
+    {
+        return std::string_view(s_.data(), s_.size());
+    }
+#endif
+
+    /** Return the string_view
+    */
+    core::string_view
+    get() const noexcept
+    {
+        return s_;
+    }
+
+    /** Dereference operator
+    */
+    core::string_view
+    operator*() const noexcept
+    {
+        return s_;
+    }
+
+    /** Member access operator
+    */
+    core::string_view const*
+    operator->() const noexcept
+    {
+        return &s_;
+    }
+
+private:
+    core::string_view s_;
+};
+
+} // capy
+} // boost
+
+#endif

test/unit/embed.cpp

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+//
+// Copyright (c) 2025 Vinnie Falco (vinnie dot falco at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// Official repository: https://github.com/cppalliance/capy
+//
+
+// Test that header file is self-contained.
+#include <boost/capy/embed.hpp>
+
+#include "test_suite.hpp"
+
+#if __cpp_lib_string_view >= 201606L
+# include <string_view>
+#endif
+
+namespace boost {
+namespace capy {
+
+namespace {
+
+embed text(R"(
+Hello "world"
+This has quotes and )
+)");
+
+} // (anon)
+
+struct embed_test
+{
+    core::string_view good =
+        "Hello \"world\"\nThis has quotes and )\n";
+
+    void check(core::string_view s)
+    {
+        BOOST_TEST_EQ(s, good);
+    }
+
+#if __cpp_lib_string_view >= 201606L
+    void check_std(std::string_view s)
+    {
+        BOOST_TEST_EQ(s, good);
+    }
+#endif
+
+    void run()
+    {
+        check(text);
+#if __cpp_lib_string_view >= 201606L
+        check_std(text);
+#endif
+        BOOST_TEST_EQ(text.get(), good);
+        BOOST_TEST_EQ(*text, good);
+        BOOST_TEST_EQ(text->data(), good);
+    }
+};
+
+TEST_SUITE(embed_test, "boost.capy.embed");
+
+} // capy
+} // boost