.. _program_listing_file_include_heaphook_utils.hpp:

Program Listing for File utils.hpp
==================================

|exhale_lsh| :ref:`Return to documentation for file <file_include_heaphook_utils.hpp>` (``include/heaphook/utils.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #pragma once
   
   #include <cstring>
   #include <cstdio>
   #include <unistd.h>
   
   // Convert the pointer type to a string
   // in the form 0xYYYYYY and write it to buf.
   // The return value is the pointer value after writing.
   // ex) when write 0x1234 then return value is buf+6.
   [[maybe_unused]]
   char * format_built_in_type(char * buf, void * ptr) noexcept;
   
   // Convert the size_t type to a decimal string
   // and write it to buf.
   // The return value is the pointer value after writing.
   [[maybe_unused]]
   char * format_built_in_type(char * buf, size_t n) noexcept;
   
   // This function writes s to buf.
   // The return value is the pointer value after writing.
   [[maybe_unused]]
   char * format_built_in_type(char * buf, const char * s) noexcept;
   
   [[maybe_unused]]
   void format(char * buf) noexcept;
   
   // Convert multiple arguments to strings, pack them into buf, and write them.
   // The only values that can be passed as arguments are instances of
   // the following types now.
   // void *, size_t , const char *
   //
   // For example, format(buf, "hello world", 1, ", ", ptr);
   // would write buf = "hello world1, 0xxxxxxxx".
   template<typename Head, typename ... Tail>
   [[maybe_unused]]
   void format(char * buf, Head head, Tail... tail) noexcept
   {
     buf = format_built_in_type(buf, head);
     format(buf, tail ...);
   }
   
   template<typename Head>
   [[maybe_unused]]
   void format_as_csv_entry(char * buf, Head head) noexcept
   {
     buf = format_built_in_type(buf, head);
     buf = format_built_in_type(buf, "\n");
     *buf = '\0';
   }
   
   template<typename Head, typename ... Tail>
   [[maybe_unused]]
   void format_as_csv_entry(char * buf, Head head, Tail... tail) noexcept
   {
     buf = format_built_in_type(buf, head);
     buf = format_built_in_type(buf, ", ");
     format_as_csv_entry(buf, tail ...);
   }
   
   template<typename ... Args, size_t BufSize = 0x400>
   [[maybe_unused]]
   void write_to_stderr(Args... args)
   {
     char buf[BufSize];
     format(buf, args ...);
     write(STDERR_FILENO, buf, strlen(buf));
   }
   
   [[maybe_unused]]
   inline bool is_power_of_2(size_t x) noexcept
   {
     return x > 0 && ((x - 1) & x) == 0;
   }
   
   [[maybe_unused]]
   inline bool is_valid_alignment(size_t alignment) noexcept
   {
     return is_power_of_2(alignment) && (alignment % sizeof(void *) == 0);
   }
   
   // if x > 0x80000000'00000000 then return 0
   [[maybe_unused]]
   inline size_t next_power_of_2(size_t x) noexcept
   {
     constexpr size_t max_x = 1ull << 63;
     if (x > max_x) {
       return 0;
     }
     size_t retval = 1;
     while (retval < x) {
       retval <<= 1;
     }
     return retval;
   }