Add extra parentheses for concept tests

Author: mborland

include/boost/math/ccmath/isinf.hpp

@@ -22,7 +22,7 @@
 namespace boost::math::ccmath {
 
 template <typename T>
-constexpr bool isinf(T x) noexcept
+constexpr bool (isinf)(T x) noexcept
 {
     if(BOOST_MATH_IS_CONSTANT_EVALUATED(x))
     {
@@ -41,11 +41,11 @@ constexpr bool isinf(T x) noexcept
 
         if constexpr (!std::is_integral_v<T>)
         {
-            return isinf(x);
+            return (isinf)(x);
         }
         else
         {
-            return isinf(static_cast<double>(x));
+            return (isinf)(static_cast<double>(x));
         }
     }
 }

include/boost/math/ccmath/isnan.hpp

@@ -21,7 +21,7 @@
 namespace boost::math::ccmath {
 
 template <typename T>
-inline constexpr bool isnan(T x)
+inline constexpr bool (isnan)(T x)
 {
     if(BOOST_MATH_IS_CONSTANT_EVALUATED(x))
     {
@@ -33,11 +33,11 @@ inline constexpr bool isnan(T x)
 
         if constexpr (!std::is_integral_v<T>)
         {
-            return isnan(x);
+            return (isnan)(x);
         }
         else
         {
-            return isnan(static_cast<double>(x));
+            return (isnan)(static_cast<double>(x));
         }
     }
 }