How to fix visual studio warning when using map.erase(key)

I'm programming for arduino in visual studio 2017 using the visual micro extension.

(I need to link a 1 byte value to a function pointer so that looking up the function corresponding to a given byte value is as efficient as possible. I thought std::map is appropriate for this.)

When using the map.erase(key) method, visual studio gives a warning:

However my project compiles without error and the method works (I have tested this in visual studio and the standard arduino IDE).

Note that this warning is not displayed in the arduino IDE

I guess this has something to do with the settings of visual studio but I can't find what the problem is.