ceil implementation

include/ccmath/math/nearest/ceil.hpp

@@ -8,7 +8,72 @@
 
 #pragma once
 
+#include "ccmath/math/compare/isinf.hpp"
+#include "ccmath/math/compare/isnan.hpp"
+
+#include <limits>
+#include <type_traits>
+
 namespace ccm
 {
+    /**
+     * @brief Computes the smallest integer value no lesser than num.
+     * @tparam T The type of the number.
+     * @param num A floating-point or integer value.
+     * @return If no errors occur, the smallest integer value no lesser than num, that is ⌈num⌉, is returned.
+     */
+    template <typename T>
+    constexpr T ceil(T num) noexcept 
+    {
+        if constexpr (std::is_floating_point_v<T>)
+		{
+			// If num is NaN, NaN is returned.
+			if (ccm::isnan(num)) { return std::numeric_limits<T>::quiet_NaN(); }
+
+			// If num is ±∞ or ±0, num is returned, unmodified.
+			if (ccm::isinf(num) || num == static_cast<T>(0)) { return num; }
+
+            // Compute the largest integer value not greater than num.
+            constexpr T num_floored = static_cast<T>(static_cast<long long int>(num));
+
+            // if num_floored is not equal to num, num_floored incremented is returned
+            if constexpr (num_floored != num) { return num_floored + 1; } 
+		}
 
+        // if num is an integer, num is returned, unmodified
+        if constexpr (std::is_integral_v<T>) { return num; }
+    }
+
+    /**
+     * @brief Computes the smallest integer value no lesser than num.
+     * @param num An integer value.
+     * @return If no errors occur, the smallest integer value no lesser than num, that is ⌈num⌉, is returned. 
+     */
+    template <typename Integer, std::enable_if_t<std::is_integral_v<Integer>, bool> = true>
+    constexpr double ceil(Integer num) noexcept 
+    {
+        return static_cast<double>(num); // All integers already have a ceil value. Just cast to double and return.
+    }
+
+    /**
+     * @brief Computes the smallest integer value no lesser than num.
+     * @param num A floating-point value.
+     * @return If no errors occur, the smallest integer value no lesser than num, that is ⌈num⌉, is returned. 
+     */
+    constexpr float ceilf(float num) noexcept
+    {
+        return ceil<float>(num);
+    }
+
+    /**
+     * @brief Computes the smallest integer value no lesser than num.
+     * @param num A floating-point value.
+     * @return If no errors occur, the smallest integer value no lesser than num, that is ⌈num⌉, is returned. 
+     */
+    constexpr double ceill(double num) noexcept
+    {
+        return ceil<double>(num);
+    }
 } // namespace ccm
+
+/// @ingroup nearest

include/ccmath/math/nearest/floor.hpp

@@ -40,7 +40,7 @@ namespace ccm
 
 	/**
 	 * @brief Computes the largest integer value not greater than num.
-	 * @param num A integer value.
+	 * @param num An integer value.
 	 * @return If no errors occur, the largest integer value not greater than num, that is ⌊num⌋, is returned.
 	 */
 	template <typename Integer, std::enable_if_t<std::is_integral_v<Integer>, bool> = true>