option: rename to to_string_opt and to_string_view_opt

to_option_string -> to_string_opt
to_string_view   -> to_string_view_opt

lib/utils/Makefile.am

@@ -58,6 +58,7 @@ libmu_utils_la_SOURCES=						\
 	mu-logger.cc						\
 	mu-logger.hh						\
 	mu-option.hh						\
+	mu-option.cc						\
 	mu-readline.cc						\
 	mu-readline.hh						\
 	mu-result.hh						\

lib/utils/meson.build

@@ -23,6 +23,7 @@ lib_mu_utils=static_library('mu-utils', [
 		  'mu-logger.cc',
 		  'mu-logger.hh',
 		  'mu-option.hh',
+                  'mu-option.cc',
 		  'mu-readline.cc',
 		  'mu-readline.hh',
 		  'mu-result.hh',

lib/utils/mu-option.hh

@@ -15,6 +15,7 @@
 #define MU_OPTION__
 
 #include "optional.hpp"
+#include <string>
 
 namespace Mu {
 
@@ -29,5 +30,31 @@ Some(T&& t)
 }
 constexpr auto Nothing = tl::nullopt; // 'None' is take already
 
+/**
+ * Maybe create a string from a const char pointer.
+ *
+ * @param str a char pointer or NULL
+ *
+ * @return option with either the string or nothing if str was NULL.
+ */
+Option<std::string>
+static inline to_string_opt(const char* str) {
+	if (str)
+		return std::string{str};
+	else
+		return Nothing;
+}
+
+/**
+ * Like maybe_string that takes a const char*, but additionally,
+ * g_free() the string.
+ *
+ * @param str char pointer or NULL (consumed)
+ *
+ * @return option with either the string or nothing if str was NULL.
+ */
+Option<std::string> to_string_opt_gchar(char*&& str);
+
+
 } // namespace Mu
 #endif /*MU_OPTION__*/

lib/utils/mu-utils.cc

@@ -43,6 +43,7 @@
 #include "mu-util.h"
 #include "mu-str.h"
 #include "mu-error.hh"
+#include "mu-option.hh"
 
 using namespace Mu;
 
@@ -352,14 +353,12 @@ Mu::time_to_string(const std::string& frm, time_t t, bool utc)
 		return {};
 	}
 
-	char* str = g_date_time_format(dt, frm.c_str()); /* always utf8 */
+	auto datestr{to_string_opt_gchar(g_date_time_format(dt, frm.c_str()))};
 	g_date_time_unref(dt);
-	if (!str) {
+	if (!datestr)
 		g_warning("failed to format time with format '%s'", frm.c_str());
-		return {};
-	}
 
-	return from_gchars(std::move(str)/*consumed*/);
+	return datestr.value_or("");
 }
 
 static std::string

lib/utils/mu-utils.hh

@@ -174,22 +174,22 @@ std::string date_to_time_t_string(int64_t t);
 std::string time_to_string(const std::string& frm, time_t t, bool utc = false) G_GNUC_CONST;
 
 
-/**
- * Create a std::string by consuming a gchar* array; this takes ownership
- * of str which should no longer be used.
- *
- * @param str a gchar* or NULL (latter taken as "")
- *
- * @return a std::string
- */
-static inline std::string
-from_gchars(gchar*&& str)
-{
-	std::string s{str ? str : ""};
-	g_free(str);
+// /**
+//  * Create a std::string by consuming a gchar* array; this takes ownership
+//  * of str which should no longer be used.
+//  *
+//  * @param str a gchar* or NULL (latter taken as "")
+//  *
+//  * @return a std::string
+//  */
+// static inline std::string
+// from_gchars(gchar*&& str)
+// {
+//	std::string s{str ? str : ""};
+//	g_free(str);
 
-	return s;
-}
+//	return s;
+// }
 
 // https://stackoverflow.com/questions/19053351/how-do-i-use-a-custom-deleter-with-a-stdunique-ptr-member
 template <auto fn>