yuge optimization of fastreadnum

include/utils.hpp

@@ -1,6 +1,8 @@
 #ifndef UTILS_HPP
 #define UTILS_HPP
 
+
+#include <charconv>
 #include <cstdint>
 #include <filesystem>
 #include <format>
@@ -20,15 +22,25 @@ ssize_t readFile(const std::string& path, char* buffer, size_t maxlen);
 ssize_t readFile(const char* path, char* buffer, size_t maxlen);
 std::string getFirstDir(const std::string_view& path);
 
-template <size_t N>
-inline int fastReadNum(const std::string& path, char (&buf)[N]) {
+/* reads a number from file REALLY fast */
+template <typename T, size_t N>
+inline void fastReadNum(const std::string& path, char (&buf)[N], T& result) {
     readFile(path, buf, N);
-    int ret = 0;
-    std::from_chars(buf, buf + N, ret);
-    return ret;
+    std::from_chars(buf, buf + N, result);
 }
 
-inline std::string pNum(auto num, uint8_t decs = 0) {
+/* reads a number slightly slower and divides it */
+template <uint32_t Divider, typename T, size_t N>
+inline void fastReadNumDiv(const std::string& path, char (&buf)[N], T& result) {
+    uint64_t temp{};
+    fastReadNum(path, buf, temp);
+    if constexpr (std::is_floating_point_v<T>)
+        result = temp / static_cast<T>(Divider);
+    else
+        result = static_cast<T>(temp / Divider);
+}
+
+inline std::string pNum(const auto num, const uint8_t decs = 0) {
     return std::format("{:.{}f}", num, decs);
 }