Why doesn’t this code use the C++ power function directly? Can someone help me with the power function in this code? [closed]

by

This function uses a technique called exponentation by squaring.

It’s a particularly efficient way of evaluating the power for integral type arguments. The standard C function uses floating point arguments, and the C standard doesn’t require an exact result even if the floating point arguments represent whole numbers.

In C++ though you can probably rely on one of the overloads of std::pow that takes integral type arguments, and cast the result, subject to your making the necessary size checks. But again even the C++ standard does not require that the best possible result is returned (cf. std::sqrt under IEEE754), although one could reasonably regard a std::pow function that does not return the correct result for integral arguments to be defective.

More Related Contents:

  1. C++ What’s the standard way to define a recursive constructor?
  2. Case-insensitive string comparison in C++ [closed]
  3. Which kind of pointer do I use when?
  4. Using arrays or std::vectors in C++, what’s the performance gap?
  5. What open source C++ static analysis tools are available? [closed]
  6. std::string to char*
  7. Is it safe to link C++17, C++14, and C++11 objects
  8. Why does pow(5,2) become 24? [closed]
  9. Is it safe to fork from within a thread?
  10. Why isn’t `int pow(int base, int exponent)` in the standard C++ libraries?
  11. c++ inline function?
  12. Why does the library linker flag sometimes have to go at the end using GCC?
  13. What is a glibc free/malloc/realloc invalid next size/invalid pointer error and how to fix it?
  14. Can I safely use OpenMP with C++11?
  15. Is there any LAME C++ wrapper\simplifier (working on Linux Mac and Win from pure code)?
  16. Object layout in case of virtual functions and multiple inheritance
  17. C++ – Why static member function can’t be created with ‘const’ qualifier
  18. How to build cmake ExternalProject while configurating main one?
  19. Efficient bitwise operations for counting bits or find the right|left most ones
  20. How to automatically register a class on creation
  21. changing the directory from inside a c program under windows using system command
  22. How to read a JSON file containing multiple root elements?
  23. Using a C string gives a warning: “Address of stack memory associated with local variable returned”
  24. How to track memory allocations in C++ (especially new/delete)
  25. Call C++ code from MATLAB?
  26. const in C vs const in C++
  27. Which greedy initializer-list examples are lurking in the Standard Library?
  28. C++ static variable in .lib does not initialize
  29. C++ view types: pass by const& or by value?
  30. #ifdef vs #if – which is better/safer as a method for enabling/disabling compilation of particular sections of code?

Leave a Comment