Added bitcast function to APMath

include/APMath/Conversion.h

@@ -0,0 +1,32 @@
+#ifndef APMATH_CONVERSION_H_
+#define APMATH_CONVERSION_H_
+
+#include <climits>
+#include <concepts>
+#include <cstddef>
+#include <cstdint>
+#include <initializer_list>
+#include <optional>
+#include <span>
+#include <string>
+#include <string_view>
+#include <utility>
+
+namespace APMath {
+
+class APInt;
+class APFloat;
+
+/// Convert value \p from to the value of type `To` with the same bit representation as \p from
+template <typename To, typename From>
+To bitcast(From const& from); // Undefined
+
+template <>
+APInt bitcast(APFloat const& from);
+
+template <>
+APFloat bitcast(APInt const& from);
+
+} // namespace APMath
+
+#endif // APMATH_CONVERSION_H_

src/Conversion.cpp

@@ -0,0 +1,31 @@
+#include <APMath/Conversion.h>
+
+#include <cassert>
+#include <bit>
+
+#include <APMath/APInt.h>
+#include <APMath/APFloat.h>
+
+using namespace APMath;
+
+template <>
+APInt APMath::bitcast(APFloat const& from) {
+    if (from.precision() == APFloatPrec::Single) {
+        return APInt(std::bit_cast<uint32_t>(from.to<float>()), 32);
+    }
+    else {
+        return APInt(std::bit_cast<uint64_t>(from.to<double>()), 64);
+    }
+}
+
+template <>
+APFloat APMath::bitcast(APInt const& from) {
+    assert((from.bitwidth() == 32 || from.bitwidth() == 64) &&
+           "Other sizes are not supported by APFloat");
+    if (from.bitwidth() == 32) {
+        return APFloat(std::bit_cast<float>(from.to<uint32_t>()), APFloatPrec::Single);
+    }
+    else {
+        return APFloat(std::bit_cast<double>(from.to<uint64_t>()), APFloatPrec::Double);
+    }
+}