Use mpf_sgn to access _mp_size in gmpxx.h.

This helps mpf2mpfr.h without changing the generated code (at least with gcc).

1 files changed, 1 insertions, 1 deletions

diff --git a/gmpxx.h b/gmpxx.h
index 389c0d424..42d331658 100644
--- a/gmpxx.h
+++ b/gmpxx.h
@@ -2113,7 +2113,7 @@ public:
   // bool fits_ldouble_p() const { return mpf_fits_ldouble_p(mp); }
 
 #if __GMPXX_USE_CXX11
-  explicit operator bool() const { return mp->_mp_size != 0; }
+  explicit operator bool() const { return mpf_sgn(mp) != 0; }
 #endif
 
   // compound assignments