Why is const-correctness specific to C++?

Question

Disclaimer: I am aware that there are two questions about the usefulness of const-correctness, however, none discussed how const-correctness is necessary in C++ as oppos

Answer 1

Anders Hejlsberg (C# architect): ... If you declare a method that takes a non-const Bla, you can't pass it a const Bla. So now you're stuck. So you gradually need a const version of everything that isn't const, and you end up with a shadow world.

So again: if you started to use "const" for some methods you usually forced to use this in most of your code. But the time spent for maintaining (typing, recompiling when some const is missing, etc.) of const-correctness in code seems greater than for fixing of possible (very rare) problems caused by not using of const-correctness at all. Thus lack of const-correctness support in modern languages (like Java, C#, Go, etc.) might result in slightly reduced development time for the same code quality.

An enhancement request ticket for implementing const correctness existed in the Java Community Process since 1999, but was closed in 2005 due to above mentioned "const pollution" and also compatibility reasons: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4211070

Although C# language has no const correctness construct but similar functionality possibly will appear soon in "Microsoft Code Contracts" (library + static analysis tools) for .NET Framework by using [Pure] and [Immutable] attributes: Pure functions in C#

Answer 2

If you are writing programs for embedded devices with data in FLASH or ROM you can't live without const-correctness. It gives you the power to control the correct handling of data in different types of memory.