added bitmask type to ..math/utils/integer_traits.hpp

Author: TomSaw

src/modm/math/utils/integer_traits.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Thomas Sommer
+ * Copyright (c) 2021-2022, Thomas Sommer
  *
  * This file is part of the modm project.
  *
@@ -32,6 +32,7 @@ struct uint_t
 		(Bits <= 64), uint64_t>>>>;
 };
 
+/// ETL also got such a trait: https://www.etlcpp.com/smallest.html
 template<int Bits>
 using least_uint = typename modm::uint_t<Bits>::least;
 
@@ -68,5 +69,25 @@ struct fits_any {
 template <typename ... Ts>
 using fits_any_t = typename fits_any<Ts...>::type;
 
+/// @ingroup modm_math_utils
+
+/// Generates a bitmask with N bits set
+/// @author		Thomas Sommer
+template<unsigned int N>
+struct bitmask {
+	using value_type = uint_t<N>::least;
+	static constexpr value_type value = std::pow(2, N) - 1;
+
+	constexpr operator value_type() const noexcept
+	{
+		return value;
+	}
+};
+
+template<unsigned int N>
+using bitmask_t = typename bitmask<N>::value_type;
+
+template<unsigned int N>
+static constexpr bitmask_t<N> bitmask_v = bitmask<N>::value;
 /// @}
-}
+} // namespace modm