olcNES | NES Emulator , and Tutorial Video Code | Video Game library

I am trying to write a chip CPU emulator and implementing its instruction table as a vector of structs where each struct contains a value and a function pointer to a particular operation. My compiler (clang++) however gives me the error:

no operator "=" matches these operands -- operand types are: std::__1::vector> = {...}

and:

no viable overloaded '='

for the line func_table = {{1,&A::func1},{2,&A::func2}};

I'm using the exact same syntax used in a similar project on GitHub but I still get these errors. It only seems to be a problem initialising with structs of non-null function pointers. I'm very new to programming with C++ so i'd love to know what I'm misunderstanding. Below is an example of the header and source file