php_random_default_engine() is not C++ conforming

[cmb69]

Description

While trying to build sqlsrv 5.12.0 against PHP 8.4.0alpha2, I've noticed

php-src/ext/random/php_random.h

Lines 168 to 174 in ce8ffed

	static inline php_random_algo_with_state php_random_default_engine(void)
	{
	return (php_random_algo_with_state){
	.algo = php_random_default_algo(),
	.state = php_random_default_status(),
	};
	}

While designated initializers are a C99 feature, they are only supported as of C++20, and that appears to stretch compiler support a bit too far.

Even worse, apparently the type cast isn't supported by MSVC (and maybe others) at all.

Replacing that function definition with the following works smoothly:

static inline php_random_algo_with_state php_random_default_engine(void)
{
	php_random_algo_with_state raws;
	raws.algo = php_random_default_algo();
	raws.state = php_random_default_status();
	return raws;
}

Maybe there is a better solution.

PHP Version

PHP 8.4

Operating System

Windows

[cmb69]

@TimWolla, since you've written that code, could you please have a look?

[TimWolla]

Is this only about php_random_default_engine() (because it's in the header) and not things like

php-src/ext/random/engine_xoshiro256starstar.c

Lines 115 to 118 in ce8ffed

	return php_random_range((php_random_algo_with_state){
	.algo = &php_random_algo_xoshiro256starstar,
	.state = state,
	}, min, max);

? Feel free to send a PR then.

[cmb69]

Yeah, that's only about the public headers, since only these need to be processed by exts written in C++.

I can follow up with a PR, but want to investigate some other build failures first.

[cmb69]

Ah, so this is apparently called compound literal which is a C99 (and up) feature, which appears not to be supported by any C++ standard (though apparently by GCC).