From 3123f3e983b816f52b85597f94851e080879033e Mon Sep 17 00:00:00 2001
From: "Dirk-Jan C. Binnema" <djcb@djcbsoftware.nl>
Date: Sat, 16 Sep 2023 11:01:51 +0300
Subject: [PATCH] mu-error: allow for adding end-user hints

---
 lib/utils/mu-error.hh | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/lib/utils/mu-error.hh b/lib/utils/mu-error.hh
index 29be7e5f..c038719f 100644
--- a/lib/utils/mu-error.hh
+++ b/lib/utils/mu-error.hh
@@ -137,7 +137,7 @@ struct Error final : public std::exception {
 	 * @return true or false
 	 */
 	constexpr bool is_soft_error() const {
-		return (static_cast<uint32_t>(code_) & SoftError) != 0;
+		return !!((static_cast<uint32_t>(code_)>>24) & SoftError);
 	}
 
 	constexpr uint8_t exit_code() const {
@@ -154,6 +154,26 @@ struct Error final : public std::exception {
 			    "%s", what_.c_str());
 	}
 
+	/**
+	 * Add an end-user hint
+	 *
+	 * @param args... libfmt-style format string and parameters
+	 *
+	 * @return the error
+	 */
+	template<typename...T>
+	Error& add_hint(fmt::format_string<T...> frm, T&&... args) {
+		hint_ = fmt::format(frm, std::forward<T>(args)...);
+		return *this;
+	}
+
+	/**
+	 * Get the hint
+	 *
+	 * @return the hint, empty for no hint.
+	 */
+	const std::string& hint() const { return hint_; }
+
 private:
 	static inline GQuark error_quark (void) {
 		static GQuark error_domain = 0;
@@ -164,9 +184,9 @@ private:
 
 	const Code		code_;
 	const std::string	what_;
+	std::string		hint_;
 };
 
-
 static inline auto
 format_as(const Error& err) {
 	return mu_format("<{} ({})>", err.what(), Error::error_number(err.code()));