Add single arg version of check non finite for nan conversions

Author: mborland

include/boost/decimal/decimal32_t.hpp

@@ -241,6 +241,9 @@ BOOST_DECIMAL_EXPORT class decimal32_t final // NOLINT(cppcoreguidelines-special
     template <typename Decimal>
     friend constexpr Decimal detail::check_non_finite(Decimal lhs, Decimal rhs) noexcept;
 
+    template <typename Decimal>
+    friend constexpr Decimal detail::check_non_finite(Decimal x) noexcept;
+
 public:
     // 3.2.2.1 construct/copy/destroy:
     constexpr decimal32_t() noexcept = default;

include/boost/decimal/detail/check_non_finite.hpp

@@ -43,6 +43,20 @@ constexpr Decimal check_non_finite(Decimal lhs, Decimal rhs) noexcept
     }
 }
 
+template <typename Decimal>
+constexpr Decimal check_non_finite(Decimal x) noexcept
+{
+    static_assert(is_decimal_floating_point_v<Decimal>, "Types must be a decimal type");
+
+    if (isnan(x))
+    {
+        return issignaling(x) ? nan_conversion(x) : x;
+    }
+
+    BOOST_DECIMAL_ASSERT(isinf(x));
+    return x;
+}
+
 } //namespace detail
 } //namespace decimal
 } //namespace boost