time/ISO8601: ParseISO8601() returns precision

src/song/Filter.cxx

@@ -120,7 +120,7 @@ ParseTimeStamp(const char *s)
 		return std::chrono::system_clock::from_time_t((time_t)value);
 
 	/* try ISO 8601 */
-	return ParseISO8601(s);
+	return ParseISO8601(s).first;
 }
 
 static constexpr bool

src/time/ISO8601.cxx

@@ -58,7 +58,8 @@ FormatISO8601(std::chrono::system_clock::time_point tp)
 	return FormatISO8601(GmTime(tp));
 }
 
-std::chrono::system_clock::time_point
+std::pair<std::chrono::system_clock::time_point,
+	  std::chrono::system_clock::duration>
 ParseISO8601(const char *s)
 {
 	assert(s != nullptr);
@@ -73,6 +74,10 @@ ParseISO8601(const char *s)
 	if (end == nullptr || *end != 0)
 		throw std::runtime_error("Failed to parse time stamp");
 
-	return TimeGm(tm);
+	std::chrono::system_clock::duration precision = std::chrono::seconds(1);
+
+	auto tp = TimeGm(tm);
+
+	return std::make_pair(tp, precision);
 #endif /* !_WIN32 */
 }

src/time/ISO8601.hxx

@@ -36,6 +36,7 @@
 #include "util/Compiler.h"
 
 #include <chrono>
+#include <utility>
 
 #include <stddef.h>
 
@@ -50,7 +51,16 @@ gcc_pure
 StringBuffer<64>
 FormatISO8601(std::chrono::system_clock::time_point tp);
 
-std::chrono::system_clock::time_point
+/**
+ * Parse a time stamp in ISO8601 format.
+ *
+ * Throws on error.
+ *
+ * @return a pair consisting of the time point and the specified
+ * precision; e.g. for a date, the second value is "one day"
+ */
+std::pair<std::chrono::system_clock::time_point,
+	  std::chrono::system_clock::duration>
 ParseISO8601(const char *s);
 
 #endif