Compilation bug with clang 3.4

[msoos]

When compiling with clang 3.4 I get:

[..]minisat/minisat/core/SolverTypes.h:55:16: error: 
      friend declaration specifying a default argument must be a definition
    friend Lit mkLit(Var var, bool sign = false);

[tscheepers]

+1

[jon-whit]

Same issue here.

[johntyree]

This can be worked around by providing another definition for mkLit.

This patch compiles cleanly for me with clang-3.7.

diff --git a/minisat/core/SolverTypes.h b/minisat/core/SolverTypes.h
index 89986d1..9875f7f 100644
--- a/minisat/core/SolverTypes.h
+++ b/minisat/core/SolverTypes.h
@@ -52,7 +52,7 @@ struct Lit {
     int     x;

     // Use this as a constructor:
-    friend Lit mkLit(Var var, bool sign = false);
+    // friend Lit mkLit(Var var, bool sign) ;

     bool operator == (Lit p) const { return x == p.x; }
     bool operator != (Lit p) const { return x != p.x; }
@@ -60,6 +60,7 @@ struct Lit {
 };


+inline  Lit  mkLit     (Var var) { bool sign = false; Lit p; p.x = var + var + (int)sign; return p; }
 inline  Lit  mkLit     (Var var, bool sign) { Lit p; p.x = var + var + (int)sign; return p; }
 inline  Lit  operator ~(Lit p)              { Lit q; q.x = p.x ^ 1; return q; }
 inline  Lit  operator ^(Lit p, bool b)      { Lit q; q.x = p.x ^ (unsigned int)b; return q; }

[msoos]

@niklasso can you please fix this? I don't agree with the fix by @johntyree because it's not clean, but we can just set the default value in the declaration+definition instead of the friend declaration. Please.... it's breaking everything.

Thanks!

Mate