Passing variable type as function parameter

You could make an enum for all different types possible, and use a switch to make the dereferencing:

typedef enum {
    CHAR,
    INT,
    FLOAT,
    DOUBLE
} TYPE;

void foo(TYPE t, void* x){
    switch(t){
        case CHAR:
            (char*)x;
            break;
        case INT:
            (int*)x;
            break;
         ...
    }
}

You can't do that for a function, because then it needs to know the types of the arguments (and any other symbols the function uses) to generate working machine code. You could try a macro like:

#define foo(type_t) ({ \
    unsigned char bar; \
    bar = ((type_t*)(&static_array))->member; \
    ... \
    })