The title of this site refers to a phrase coined by Scott Meyers. The most vexing parse is a result of the ambiguity of function declarations and variable definitions in C++, but I also think it’s a fun sequence of words. You’ve probably run into this while trying to define a variable with a call to a default constructor. That happens pretty frequently, so get in the habit of of doing so correctly: by omitting the empty parentheses, as in string str rather than string str(). This is necessary because the latter is ambiguous: ...