This function works well in the following testcase: void draw() { // When cursor is here, WhatFunction() shows "draw" glClear(GL_COLOR_BUFFER_BIT {{|}} GL_DEPTH_BUFFER_BIT); } typedef struct { int ident; // { <- braces in comments are ignored thanks to %. Great! int version; // here it shows "} HEADER" } HEADER; # define EX(a, b, c, d) a enum CMD_index #endif { EX(CMD_append, "append", ex_append); // here "enum CMD_index..." }; class Sys { public: load() { // NG: here, it shows "Sys" instead of "load"... } }; class Camera : public Object { public: void init(); }; void Camera::init() { // here WhatFunction shows "init" }