Do class/struct members always get created in memory in the order they were declared?

by

C99 §6.7.2.1 clause 13 states:

Within a structure object, the
non-bit-field members and the units in
which bit-fields reside have addresses
that increase in the order in which
they are declared.

and goes on to say a bit more about padding and addresses. The C89 equivalent section is §6.5.2.1.

C++ is a bit more complicated. In the 1998 and 2003 standards, there is §9.2 clause 12 (clause 15 in C++11):

Nonstatic data members of a
(non-union) class declared without an
intervening access-specifier are
allocated so that later members have
higher addresses within a class
object. The order of allocation of
nonstatic data members separated by an
access-specifier is unspecified
(11.1). Implementation alignment
requirements might cause two adjacent
members not to be allocated
immediately after each other; so might
requirements for space for managing
virtual functions (10.3) and virtual
base classes (10.1).

More Related Contents:

  1. Memory alignment in C-structs
  2. How to judge an address as legal or illegal by it‘s numerical value？ [closed]
  3. Dynamic memory allocation in game server [closed]
  4. When and why will a compiler initialise memory to 0xCD, 0xDD, etc. on malloc/free/new/delete?
  5. What is memory fragmentation?
  6. stringstream, string, and char* conversion confusion
  7. General guidelines to avoid memory leaks in C++ [closed]
  8. Making std::vector allocate aligned memory
  9. Why do compilers allow string literals not to be const?
  10. How to read file content into istringstream?
  11. Difference between pointer to a reference and reference to a pointer
  12. Create new C++ object at specific memory address?
  13. What is a glibc free/malloc/realloc invalid next size/invalid pointer error and how to fix it?
  14. What happens when a computer program runs?
  15. How do you determine the size of an object in C++?
  16. How do you read directly from physical memory on Windows?
  17. Could I ever want to access the address zero?
  18. Read process memory of a process does not return everything
  19. Can I Allocate a specific memory address using pointers in c++?
  20. Is std::vector memory freed upon a clear?
  21. When is a type in c++11 allowed to be memcpyed?
  22. Is global memory initialized in C++?
  23. Heap corruption under Win32; how to locate?
  24. Linux Allocator Does Not Release Small Chunks of Memory
  25. Dereferencing deleted pointers always result in an Access Violation?
  26. Aligning static string literals
  27. Memory alignment : how to use alignof / alignas?
  28. Do I really have to worry about alignment when using placement new operator?
  29. how do arrays work internally in c/c++
  30. How to ignore false positive memory leaks from _CrtDumpMemoryLeaks?

Leave a Comment