Fix signbit detection (#423)

(cherry picked from commit def687462c)
2017-06-08 11:28:39 +02:00
parent b9a20d761a
commit baedba07ca
1 changed files with 3 additions and 1 deletions
@@ -397,8 +397,10 @@ class numeric_limits<fmt::internal::DummyInt> :
  // Portable version of signbit.
  static bool isnegative(double x) {
    using namespace fmt::internal;
-    if (const_check(sizeof(signbit(x)) == sizeof(int)))
+    if (const_check(sizeof(signbit(x)) == sizeof(bool) ||
+                    sizeof(signbit(x)) == sizeof(int))) {
      return signbit(x) != 0;
+    }
    if (x < 0) return true;
    if (!isnotanumber(x)) return false;
    int dec = 0, sign = 0;