Question

Everything was compiling until I added vector<Move> bestLine;

search.h

#ifndef SEARCH_H
#define SEARCH_H

#include <vector>
#include "types.h"
#include "position.h"
#include "move.h"
#include "moves.h"

U8 searchDepth;
U8 searchCount;
vector<Move> bestLine; // The compiler doesn't like this.

void searchPosition(Position &P, U8 depth);
void searchMove(Move &M);

#endif

The errors I’m receiving are:

1>d:\test\search.h(12): error C2143: syntax error : missing ';' before '<'
1>d:\test\search.h(12): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
1>d:\test\search.cpp(30): error C2065: 'bestLine' : undeclared identifier

It seems that the compiler isn’t recognizing Move, so bestLine isn’t being declared. I thought it might be a circular dependency and tried declaring an incomplete type for Move, but it had no effect. Can someone explain what I’m missing?

Answer 1

Actually qualifying is not enough, although necessary:

std::vector<Move> bestLine;

This also constitutes a definition, and, if in a header, you risk having linker errors.

You should declare it extern and define it in a single implementation file:

//search.h
//...
extern std::vector<Move> bestLine;

//search.cpp
//...
std::vector<Move> bestLine;