mahmood questions

• possible inconsistency in std::vector while erasing an element [duplicate]
• Verbose output for cmake command
• "undefined symbol" during execution in C++
• NULL statement in VHDL
• Checking for variable to be non-empty in bash
• Appending row to dataframe with concat()
• undefined reference to `tan' but math.h has been included
• how to change the color of an arrow
• operator== overloading considering non-static member function
• yet another issue with call by value|reference

mahmood answers