Add power of 10 function

Author: mborland

include/boost/decimal/detail/is_power_of_10.hpp

@@ -0,0 +1,28 @@
+// Copyright 2025 Matt Borland
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#ifndef BOOST_DECIMAL_DETAIL_IS_POWER_OF_10_HPP
+#define BOOST_DECIMAL_DETAIL_IS_POWER_OF_10_HPP
+
+#include <boost/decimal/detail/config.hpp>
+#include <boost/decimal/detail/remove_trailing_zeros.hpp>
+#include <boost/decimal/detail/concepts.hpp>
+
+namespace boost {
+namespace decimal {
+namespace detail {
+
+template <typename T>
+constexpr auto is_power_of_10(const T x) noexcept
+    BOOST_DECIMAL_REQUIRES_RETURN(detail::is_unsigned_v, T, bool)
+{
+    const auto removed_zeros {detail::remove_trailing_zeros(x)};
+    return removed_zeros.trimmed_number == 1U;
+}
+
+} // namespace detail    
+} // namespace decimal
+} // namespace boost
+
+#endif // BOOST_DECIMAL_DETAIL_IS_POWER_OF_10_HPP