Re: Violation of principle that plan trees are read-only

On 20/5/25 22:43, Nico Williams wrote:
> [snip]
> What you want is for C to have a type attribute that denotes
> immutability all the way down.  `const` doesn't do that.  One thing that
> could be done is to write a utility that creates const-all-the-way-down
> clones of given types, but such a tool can't be written as C
> pre-processor macros -- it would have to be a tool that parses the
> actual type definitions, or uses DWARF or similar to from the
> compilation of a file (I've done this latter before, but this weds you
> to compilers that output DWARF, which MSVC doesn't, for example).
>
> Really, the C committee ought to add this at some point, darn it.  It
> would be the opposite of Rust's &mut.

Like C++'s const specifier, specially const references to objects?  This 
is actually natively compatible with C code, "just" by throwing extern 
"C" around.....

     https://en.cppreference.com/w/cpp/language/cv

(most of Postgres' code is already "Object-oriented in C" in my view...)


The fact that the C++ compiler is usually able to optimize deeper/better 
than a C one due to aggresive inlining+global optimization and inferred 
"strict"ness doesn't hurt either :)


My €.02.  HTH.

     / J.L.

-- 
Parkinson's Law: Work expands to fill the time alloted to it.