1 files changed, 91 insertions, 0 deletions
diff --git a/nihil.ucl/boolean.ccm b/nihil.ucl/boolean.ccm
new file mode 100644
index 0000000..068dfdd
--- /dev/null
+++ b/nihil.ucl/boolean.ccm
@@ -0,0 +1,91 @@
+/*
+ * This source code is released into the public domain.
+ */
+
+module;
+
+#include <cassert>
+#include <cstdint>
+#include <cstdlib>
+#include <expected>
+#include <format>
+#include <string>
+
+#include <ucl.h>
+
+export module nihil.ucl:boolean;
+
+import :object;
+
+namespace nihil::ucl {
+
+export struct boolean final : object {
+	using contained_type = bool;
+
+	inline static constexpr object_type ucl_type = object_type::boolean;
+
+	/*
+	 * Create a boolean holding the value false.  Throws std::system_error
+	 * on failure.
+	 */
+	boolean();
+
+	/*
+	 * Create a boolean holding a specific value.  Throws std::system_error
+	 * on failure.
+	 */
+	explicit boolean(bool);
+
+	/*
+	 * Create a new boolean from a UCL object.  Throws type_mismatch
+	 * on failure.
+	 */
+	boolean(ref_t, ::ucl_object_t const *uobj);
+	boolean(noref_t, ::ucl_object_t *uobj);
+
+	// Return this object's value.
+	auto value(this boolean const &self) -> contained_type;
+};
+
+/*
+ * Boolean constructors.  These return an error instead of throwing.
+ */
+
+export [[nodiscard]] auto
+make_boolean(boolean::contained_type = false) -> std::expected<boolean, error>;
+
+/*
+ * Comparison operators.
+ */
+
+export auto operator== (boolean const &a, boolean const &b) -> bool;
+export auto operator== (boolean const &a, boolean::contained_type b) -> bool;
+export auto operator<=> (boolean const &a, boolean const &b)
+	-> std::strong_ordering;
+export auto operator<=> (boolean const &a, boolean::contained_type b)
+	-> std::strong_ordering;
+
+} // namespace nihil::ucl
+
+/*
+ * std::formatter for a boolean.  This provides the same format operations
+ * as std::formatter<bool>.
+ */
+export template<>
+struct std::formatter<nihil::ucl::boolean, char>
+{
+	std::formatter<bool> base_formatter;
+
+	template<class ParseContext>
+	constexpr ParseContext::iterator parse(ParseContext& ctx)
+	{
+		return base_formatter.parse(ctx);
+	}
+
+	template<class FmtContext>
+	FmtContext::iterator format(nihil::ucl::boolean const &o,
+				    FmtContext& ctx) const
+	{
+		return base_formatter.format(o.value(), ctx);
+	}
+};