document clockid_t helper

diff --git a/src/timefunc.cpp b/src/timefunc.cpp
index b486de1..e41308f 100644 (file)
--- a/src/timefunc.cpp
+++ b/src/timefunc.cpp
@@ -1019,6 +1019,18 @@ namespace clock {
 
     namespace {
 
+        /**
+         * @brief         <b>For internal use only</b>. Translates clock
+         *                specification flags to kernel clock types.
+         *
+         * @param id      Master clock id: \c mono, \c real, \c boot, or \c
+         *                cpu.
+         * @param var     Variant of clock if appropriate: \c raw, \c exact, \c
+         *                process, or \c thread. Use \c dflt for the base
+         *                variant.
+         *
+         * @return        The clock id for using with kernel APIs.
+         */
         static inline clockid_t
         clockid_of_flags (const enum type::id      id,
                           const enum type::variant var) NOEXCEPT