From 77de9119efbee9e65f0b50fc8b9315b6fb0910fb Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Fri, 20 Mar 2026 17:59:56 +0100
Subject: Added support for _BitInt (available in clang)

---
 bitint_wrapper.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 bitint_wrapper.h

(limited to 'bitint_wrapper.h')

diff --git a/bitint_wrapper.h b/bitint_wrapper.h
new file mode 100644
index 0000000..785d0fa
--- /dev/null
+++ b/bitint_wrapper.h
@@ -0,0 +1,50 @@
+#ifndef BITINT_WRAPPER_H
+#define BITINT_WRAPPER_H
+
+#include <cstdio>
+#include <iostream>
+
+// Wrapper class for _BitInt(N) (port of the C23 feature, compiler
+// extension for C++ available in Clang and maybe GCC). This is needed
+// because operator<< is not defined on _BitInt(N), apparently.
+
+template<uint64_t N = 128>
+class BitInt {
+public:
+	_BitInt(N) x;
+
+	constexpr BitInt() : x{_BitInt(N)(0)} {}
+	constexpr BitInt(int n) : x{_BitInt(N)(n)} {}
+	constexpr BitInt(long long n) : x{_BitInt(N)(n)} {}
+	constexpr BitInt(_BitInt(N) n) : x{n} {}
+	constexpr auto operator<=>(const BitInt& b) const { return x <=> b.x; }
+	constexpr bool operator==(const BitInt& b) const = default;
+	constexpr BitInt operator+(const BitInt& b) const { return x + b.x; }
+	constexpr BitInt operator-(const BitInt& b) const { return x - b.x; }
+	constexpr BitInt operator*(const BitInt& b) const { return x * b.x; }
+	constexpr BitInt operator/(const BitInt& b) const { return x / b.x; }
+	constexpr BitInt operator%(const BitInt& b) const { return x % b.x; }
+	constexpr BitInt operator-() const { return -x; }
+	constexpr BitInt operator+=(const BitInt& b) { return *this = *this + b; }
+	constexpr BitInt operator-=(const BitInt& b) { return *this = *this - b; }
+	constexpr BitInt operator*=(const BitInt& b) { return *this = *this * b; }
+	constexpr BitInt operator/=(const BitInt& b) { return *this = *this / b; }
+	constexpr BitInt operator%=(const BitInt& b) { return *this = *this % b; }
+
+	friend std::ostream& operator<<(std::ostream& os, const BitInt<N>& b) {
+		if (b > 0) {
+			std::string s;
+			auto bb = b;
+			while (bb != 0) {
+				char c = (bb.x % 10) + '0';
+				s = c + s;
+				bb /= 10;
+			}
+			return os << s;
+		} else if (b < 0) {
+			return os << "-" << -b;
+		} else return os << "0";
+	}
+};
+
+#endif
-- 
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