1 files changed, 118 insertions, 0 deletions
diff --git a/src/nanosecond.inl b/src/nanosecond.inl
new file mode 100644
index 00000000..6527dc02
--- /dev/null
+++ b/src/nanosecond.inl
@@ -0,0 +1,118 @@
+#pragma once
+#include "compat/assert.hpp"
+#include "nanosecond.hpp"
+
+namespace floormat {
+
+template<typename T>
+requires (std::is_same_v<T, double>)
+Ns operator*(const Ns& lhs, T b)
+{
+    constexpr double max{uint64_t{1} << 53};
+    auto a = lhs.stamp;
+    fm_assert(b >= 0);
+    fm_assert(b <= max);
+    auto x = double(a) * b;
+    fm_assert(x >= 0);
+    fm_assert(x <= max);
+    return Ns{(uint64_t)x};
+}
+
+constexpr Ns operator+(const Ns& lhs, const Ns& rhs)
+{
+    constexpr auto max = (uint64_t)-1;
+    auto a = lhs.stamp, b = rhs.stamp;
+    fm_assert(max - a >= b);
+    return Ns{a + b};
+}
+
+constexpr Ns operator-(const Ns& lhs, const Ns& rhs)
+{
+    auto a = lhs.stamp, b = rhs.stamp;
+    fm_assert(a >= b);
+    return Ns{a - b};
+}
+
+template<typename T>
+requires (std::is_integral_v<T> && std::is_unsigned_v<T>)
+constexpr Ns operator*(const Ns& lhs, T rhs)
+{
+    auto a = lhs.stamp, b = uint64_t{rhs};
+    auto x = a * b;
+    fm_assert(b == 0 || x / b == a);
+    return Ns{x};
+}
+
+template<typename T>
+requires (std::is_integral_v<T> && std::is_signed_v<T> && sizeof(T) < sizeof(uint64_t))
+constexpr Ns operator*(const Ns& lhs, T rhs)
+{
+    fm_assert(rhs >= T{0});
+    auto b = uint64_t(rhs);
+    auto x = lhs.stamp * b;
+    fm_assert(b == 0 || x / b == lhs.stamp);
+    return Ns{x};
+}
+
+template<typename T>
+constexpr Ns operator*(T lhs, const Ns& rhs)
+{
+    return rhs * lhs;
+}
+
+template<typename T>
+requires std::is_same_v<float, T>
+constexpr Ns operator*(const Ns& lhs, T rhs)
+{
+    constexpr float max{uint64_t{1} << 24};
+    auto a = lhs.stamp;
+    auto x = float(a) * float{rhs};
+    fm_assert(x >= 0);
+    fm_assert(x <= max);
+    return Ns{uint64_t(x)};
+}
+
+constexpr uint64_t operator/(const Ns& lhs, const Ns& rhs)
+{
+    auto a = lhs.stamp, b = rhs.stamp;
+    fm_assert(b != 0);
+    return a / b;
+}
+
+constexpr Ns operator/(const Ns& lhs, uint64_t b)
+{
+    auto a = lhs.stamp;
+    fm_assert(b != 0);
+    return Ns{a / b};
+}
+
+constexpr uint64_t operator%(const Ns& lhs, const Ns& rhs)
+{
+    auto a = lhs.stamp, b = rhs.stamp;
+    fm_assert(b != 0);
+    return a % b;
+}
+
+constexpr Ns operator%(const Ns& lhs, uint64_t b)
+{
+    auto a = lhs.stamp;
+    fm_assert(b != 0);
+    return Ns{a % b};
+}
+
+constexpr Ns& operator+=(Ns& lhs, const Ns& rhs)
+{
+    constexpr auto max = (uint64_t)-1;
+    auto b = rhs.stamp;
+    fm_assert(max - lhs.stamp >= b);
+    lhs.stamp += b;
+    return lhs;
+}
+
+constexpr std::strong_ordering operator<=>(const Ns& lhs, const Ns& rhs)
+{
+    auto a = lhs.stamp, b = rhs.stamp;
+    return a <=> b;
+}
+
+} // namespace floormat