I see code like this from time to time. Are the leading underscores significant, in general, in the D language? Is it just programmer preference? Is it a coding practice, in general, that is common...even outside of D? Thanks for any assistance.

From: http://dpldocs.info/this-week-in-d/Blog.Posted_2022_10_10.html#hello-arduino

import ldc.llvmasm;

// Ports from the delay_basic.h in the thing
void _delay_loop_1(ubyte __count) {
	// this template param is required to avoid
	// assertion `!Call.getType()->isVoidTy() && "Bad inline asm!"' failed.

        __asm!ubyte (
                "1: dec $0\n\tbrne 1b",
                "=r,0", (__count)
        );
}
void _delay_loop_2(ushort __count) {
        __asm!ushort (`
	1: sbiw $0,1
	brne 1b
	`,
	`=w,0`,
	__count);
}

// port from delay.h in arduino thing
enum F_CPU = 1_000_000UL;

// this was _delay_ms but i did something wrong and changed double to int and i still don't love it
void _delay(int __ms) {
	ushort __ticks;
	ulong __tmp = (F_CPU * __ms) / 4000;
	if(__tmp < 1)
		__ticks = 1;
	else if(__tmp > 65_535) {
		__ticks = cast(ushort) (__ms * 10.0);
		while(__ticks) {
			_delay_loop_2(cast(ushort) (((F_CPU) / 4e3) / 10));
			__ticks--;
		}
		return;
	} else
		__ticks = cast(ushort) __tmp;
	_delay_loop_2(__ticks);
}

On Saturday, 17 December 2022 at 02:42:22 UTC, Paul wrote:

The only important thing you should know about is that doubly leading underscores are reserved for symbols generated by the D front-end, so you should avoid them. This is specified here: https://dlang.org/spec/lex.html#identifiers.