Added comments

src/core/support/string.h

@@ -86,16 +86,20 @@ int gpr_asprintf(char **strp, const char *format, ...);
    if it is non-null. */
 char *gpr_strjoin(const char **strs, size_t nstrs, size_t *total_length);
 
-/* A vector of strings... addition takes ownership of strings */
+/* A vector of strings... for building up a final string one piece at a time */
 typedef struct {
   char **strs;
   size_t count;
   size_t capacity;
 } gpr_strvec;
 
+/* Initialize/destroy */
 void gpr_strvec_init(gpr_strvec *strs);
 void gpr_strvec_destroy(gpr_strvec *strs);
+/* Add a string to a strvec, takes ownership of the string */
 void gpr_strvec_add(gpr_strvec *strs, char *add);
+/* Return a joined string with all added substrings, optionally setting
+   total_length as per gpr_strjoin */
 char *gpr_strvec_flatten(gpr_strvec *strs, size_t *total_length);
 
 #ifdef __cplusplus