d前置下划线

原文

import ldc.llvmasm;

void _delay_loop_1(ubyte __count) {
        __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);
}

enum F_CPU = 1_000_000UL;

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);
}

双前下划线是为D前端生成的符号保留的,因此应该避免使用它们.参考