error: invalid conversion from ‘const char*’ to ‘char’ [-fpermissive] [duplicate]

Answer 1

Try replacing

 char c = "i";

with

 char c = 'i';

Answer 2

"i" is a string literal, you probably wanted a char literal: 'i'.

String literals are null terminated arrays of const char (which are implicitly converted to char const* when used in that expression, hence the error).

char literals are just chars

Answer 3

"i" is not a character, it's a character array that basically decays to a pointer to the first element.

You almost certainly want 'i'.

Alternatively, you may actually want a lookup based on more than a single character, in which case you should be using "i" but the type in that case is const char * rather than just char, both when defining c and in the base::lookup() method.

However, if that were the case, I'd give serious thought to using the C++ std::string type rather than const char *. It may not be necessary, but using C++ strings may make your life a lot easier, depending on how much you want to manipulate the actual values.