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zmod/CMakeLists.txt

@@ -0,0 +1,3 @@
+add_library(zmod INTERFACE)
+target_link_libraries(zmod PkgConfig::GMP)
+target_include_directories(zmod PUBLIC include)

zmod/include/zmod.hpp

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+#ifndef ZMOD_HPP_
+#define ZMOD_HPP_
+
+#include <iostream>
+#include <gmpxx.h>
+
+namespace zmod {
+
+template <unsigned long Mod>
+class ZMod {
+  mpz_class value;
+
+public:
+  ZMod() : value {} {}
+  ZMod(long value) : ZMod{mpz_class{value}} {}
+  ZMod(mpz_class value) {
+    mpz_mod_ui(this->value.get_mpz_t(), value.get_mpz_t(), Mod);
+  }
+
+  auto operator+(ZMod const& rhs) const -> ZMod {
+    return {value + rhs.value};
+  }
+
+  auto operator-() const -> ZMod {
+    return {-value};
+  }
+
+  auto operator-(ZMod const& rhs) const -> ZMod {
+    return {value - rhs.value};
+  }
+
+  auto operator*(ZMod const& rhs) const -> ZMod {
+    return {value * rhs.value};
+  }
+
+  auto inverse() const -> ZMod {
+    mpz_class m{Mod};
+    ZMod result;
+    mpz_invert(result.value.get_mpz_t(), value.get_mpz_t(), m.get_mpz_t());
+    return result;
+  }
+
+  auto friend operator<<(std::ostream & out, ZMod<Mod> const& x) -> std::ostream & {
+    return out << x.value.get_ui();
+  }
+};
+
+}
+
+#endif

zmod/src/zmod.cpp

@@ -0,0 +1 @@
+#include <zmod.hpp>