Re: [Boost-users] BOOST_PP_SEQ_ENUM troubles

Subject: Re: [Boost-users] BOOST_PP_SEQ_ENUM troubles
From: Cherotek Music (cherotek_at_[hidden])
Date: 2016-07-07 17:57:51

Thanks for the suggestion but I still can't get it to work :(

#define SEQ_FORMATS BOOST_PP_VARIADIC_TO_SEQ(FORMATS)
#define ARG_PAIR(x) {#x, create<x##File>}
#define NTH_ARG(z, n, data) ARG_PAIR(BOOST_PP_SEQ_ELEM(n, data))
#define ARG_PAIRS BOOST_PP_ENUM(BOOST_PP_SEQ_SIZE(SEQ_FORMATS), NTH_ARG,
SEQ_FORMATS)

gives the following error:

test.h:14:63: error: pasting ")" and "File" does not give a valid
preprocessing token
 #define NTH_ARG(z, n, data) ARG_PAIR(BOOST_PP_SEQ_ELEM(n, data))
                                                               ^
test.h:13:33: note: in definition of macro ‘ARG_PAIR’
 #define ARG_PAIR(x) {#x, create<x##File>}

We're getting closer though

On Thu, Jul 7, 2016 at 6:19 PM, Mathias Gaunard <
mathias.gaunard_at_[hidden]> wrote:

> On 6 July 2016 at 22:27, Cherotek Music <cherotek_at_[hidden]> wrote:
>
>> Hi,
>> I'm trying to make a macro chain that expands something like this
>>
>> *A, B, C*
>>
>> into something like this
>>
>> *{"A", create<AFile>}, {"B", create<BFile>}, {"C", create<CFile>}*
>>
>> This is what I have come up with
>>
>> *#define FORMATS A, B, C // Add new formats here*
>> *#define SEQ_FORMATS BOOST_PP_VARIADIC_TO_SEQ(FORMATS)*
>> *#define ARG_PAIR(s, data, x) {#x, create<x##File>}*
>> *#define SEQ_ARG_PAIRS BOOST_PP_SEQ_TRANSFORM(ARG_PAIR, ~, SEQ_FORMATS)*
>> *#define ARG_PAIRS BOOST_PP_SEQ_ENUM(SEQ_ARG_PAIRS)*
>>
>
> Use BOOST_PP_ENUM with BOOST_PP_SEQ_SIZE and BOOST_PP_SEQ_ELEM instead of
> BOOST_PP_SEQ_TRANSFORM+BOOST_PP_SEQ_ENUM.
>
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