C++26 programming language: simplified handling of pointer addresses

With C++26 it is possible to print the address of any pointer.

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C++20

bus pointer type void, const void And std::nullptr_t are valid. If you want to display the address of a pointer, you must put it (const) void* Change.

// formatPointer20.cpp

#include 
#include 
#include 

int main() {

  double d = 123.456789;

  //std::cout << "&d" << std::format("{}", &d) << '\n';  
  std::cout << "static_cast(&d): " << std::format("{}", static_cast(&d)) << '\n';     
  std::cout << "static_cast(&d): " << std::format("{}", static_cast(&d)) << '\n'; 
  std::cout << "nullptr: " << std::format("{}", nullptr) << '\n';           
             
}

In mainthe task becomes one double-variable named d with value 123,456789 Started. Celebration std::format Represents the address.

Tries to get the address of the first commented out line d straight along std::format(„{}“, &d) to spend. This line is commented out because it will result in a compilation error. Celebration std::format pointer must be inside void* Or const void* Changed to format it correctly.

The next three lines explain how to use pointers. std::format Formatted and output correctly. The first of these lines contains the address of d after conversion to void* Were issued. The address in the second line is d after conversion to const void* Were issued. The third row shows the values nullptr Output, which represents a null pointer.

Here is the output of the program:

When activating a commented out line, a long error message appears.

C++26

With C++26 you can output the pointer directly:

// formatPointer26.cpp

#include 
#include 
#include 

int main() {

  double d = 123.456789;
  double* p = &d;

  std::cout << "&d" << std::format("{:P}", p) << '\n';  
 
}

Frankly, the program can’t be compiled. it contradicts Compiler support for C++26 and offer P2510R3I will reveal why this is so in my next post.

What will happen next?

Concurrency will get two nice features for lock-free data structures with C++26: read-copy updates and hazard pointers.

(rme)