help on how to wrap a C macros when binding linux/spi/spidev.h

[dangbinghoo]

On Thursday, 29 March 2018 at 09:02:16 UTC, Nicholas Wilson wrote:
> On Thursday, 29 March 2018 at 08:47:50 UTC, dangbinghoo wrote:
>
>>  * #define SPI_MSGSIZE(N) \
>> 	((((N)*(sizeof (struct spi_ioc_transfer))) < (1 << 
>> _IOC_SIZEBITS)) \
>> 		? ((N)*(sizeof (struct spi_ioc_transfer))) : 0)
>>  */
>> extern (D) size_t SPI_MSGSIZE(size_t N)
>> {
>>     return ((N * (spi_ioc_transfer.sizeof)) < (1 << 
>> _IOC_SIZEBITS)) ? (N * (spi_ioc_transfer.sizeof)) : 0;
>> }
>>
>> /* #define SPI_IOC_MESSAGE(N) _IOW(SPI_IOC_MAGIC, 0, 
>> char[SPI_MSGSIZE(N)]) */
>> extern (D) auto SPI_IOC_MESSAGE(size_t N)
>> {
>>     size_t n = SPI_MSGSIZE(N);
>>     return _IOW!(char[static n])(SPI_IOC_MAGIC, 0);
>>     //mixin("return _IOW!(char[n])(SPI_IOC_MAGIC, 0);");
>> }
>> ```
>>
>
> try
>
>> extern (D) auto SPI_IOC_MESSAGE(size_t N)()
>> {
>>     enum n = SPI_MSGSIZE(N);
>>     return _IOW!(char[n])(SPI_IOC_MAGIC, 0);
>>     //mixin("return _IOW!(char[n])(SPI_IOC_MAGIC, 0);");
>> }

thanks for your reply, but it will also fail, the compiler just 
gives me :

----
source/spidev.d-mixin-129(129,8): Error: variable n cannot be 
read at compile time
----