1 files changed, 112 insertions, 0 deletions
diff --git a/nihil.ucl/real.ccm b/nihil.ucl/real.ccm
new file mode 100644
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+++ b/nihil.ucl/real.ccm
@@ -0,0 +1,112 @@
+/*
+ * This source code is released into the public domain.
+ */
+
+module;
+
+#include <compare>
+#include <expected>
+#include <format>
+#include <utility>
+
+#include <ucl.h>
+
+export module nihil.ucl:real;
+
+import :object;
+import :type;
+
+namespace nihil::ucl {
+
+export struct real final : object {
+	using contained_type = double;
+
+	inline static constexpr object_type ucl_type = object_type::real;
+
+	/*
+	 * Create a real holding the value 0.  Throws std::system_error
+	 * on failure.
+	 */
+	real();
+
+	/*
+	 * Create a real holding a specific value.  Throws std::system_error
+	 * on failure.
+	 */
+	explicit real(contained_type value);
+
+	/*
+	 * Create a new real from a UCL object.  Throws type_mismatch
+	 * on failure.
+	 */
+	real(ref_t, ::ucl_object_t const *uobj);
+	real(noref_t, ::ucl_object_t *uobj);
+
+	// Return the value of this real.
+	[[nodiscard]] auto value(this real const &self) -> contained_type;
+};
+
+/*
+ * Real constructors.  These return an error instead of throwing.
+ */
+
+export [[nodiscard]] auto
+make_real(real::contained_type = 0) -> std::expected<real, error>;
+
+/*
+ * Comparison operators.
+ */
+
+export [[nodiscard]] auto operator== (real const &a, real const &b) -> bool;
+
+export [[nodiscard]] auto operator== (real const &a,
+				      real::contained_type b) -> bool;
+
+export [[nodiscard]] auto operator<=> (real const &a, real const &b)
+	-> std::partial_ordering;
+
+export [[nodiscard]] auto operator<=> (real const &a, real::contained_type b)
+	-> std::partial_ordering;
+
+/*
+ * Literal operator.
+ */
+inline namespace literals {
+export constexpr auto operator""_ucl (long double d) -> real
+{
+	if (d > static_cast<long double>(std::numeric_limits<double>::max()) ||
+	    d < static_cast<long double>(std::numeric_limits<double>::min()))
+		throw std::out_of_range("literal out of range");
+
+	return real(static_cast<double>(d));
+}
+} // namespace nihil::ucl::literals
+
+} // namespace nihil::ucl
+
+namespace nihil { inline namespace literals {
+	export using namespace ::nihil::ucl::literals;
+}} // namespace nihil::literals
+
+/*
+ * std::formatter for a real.  This provides the same format operations
+ * as std::formatter<double>;
+ */
+export template<>
+struct std::formatter<nihil::ucl::real, char>
+{
+	std::formatter<double> base_formatter;
+
+	template<class ParseContext>
+	constexpr ParseContext::iterator parse(ParseContext& ctx)
+	{
+		return base_formatter.parse(ctx);
+	}
+
+	template<class FmtContext>
+	FmtContext::iterator format(nihil::ucl::real const &o,
+				    FmtContext& ctx) const
+	{
+		return base_formatter.format(o.value(), ctx);
+	}
+};