BOOST_PP_SEQ_ENUM troubles

Cherotek Music

6 Jul 2016 6 Jul '16

9:27 p.m.

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}* *#define SEQ_ARG_PAIRS BOOST_PP_SEQ_TRANSFORM(ARG_PAIR, ~, SEQ_FORMATS)* *#define ARG_PAIRS BOOST_PP_SEQ_ENUM(SEQ_ARG_PAIRS)* The SEQ_ARG_PAIRS macro does expand into *({"A", create<AFile>}) ({"B", create<BFile>}) ({"C", create<CFile>})* but ARG_PAIRS fails with the following error: test.cpp:20:1: error: macro "BOOST_PP_SEQ_SIZE_0" passed 2 arguments, but takes just 1 ARG_PAIRS ^ BOOST_PP_SEQ_ENUM_0 ({"B", create<BFile>}) ({"C", create<CFile>}) ({"A", create<AFile>}) ({"B", create<BFile>}) ({"C", create<CFile>}) Any ideas? thanks a lot

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Edward Diener

6 Jul 6 Jul

11:49 p.m.

On 7/6/2016 5:27 PM, Cherotek Music 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}* *#define SEQ_ARG_PAIRS BOOST_PP_SEQ_TRANSFORM(ARG_PAIR, ~, SEQ_FORMATS)* *#define ARG_PAIRS BOOST_PP_SEQ_ENUM(SEQ_ARG_PAIRS)*

The SEQ_ARG_PAIRS macro does expand into

*({"A", create<AFile>}) ({"B", create<BFile>}) ({"C", create<CFile>})*

but ARG_PAIRS fails with the following error:

test.cpp:20:1: error: macro "BOOST_PP_SEQ_SIZE_0" passed 2 arguments, but takes just 1 ARG_PAIRS ^ BOOST_PP_SEQ_ENUM_0 ({"B", create<BFile>}) ({"C", create<CFile>}) ({"A", create<AFile>}) ({"B", create<BFile>}) ({"C", create<CFile>})

Any ideas?

The reason for this is because after your transformation you do not have a valid seq anymore for BOOST_PP_SEQ_ENUM. Each seq element must be a one element tuple. The comma ( ',' ) in each seq element no longer makes that seq element valid, producing a two element tuple. Something like '({"A", create<AFile>})' really containes two elements of data, the first one being '{"A"' and the second one being 'create<AFile>}'.

...

thanks a lot

Cherotek Music

7 Jul 7 Jul

7:04 a.m.

Thanks I see. I'm at work now and can't test it but would replacing the comma in ARG_PAIR with *BOOST_PP_COMMA help?* On Thu, Jul 7, 2016 at 1:49 AM, Edward Diener wrote:

...

On 7/6/2016 5:27 PM, Cherotek Music 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}* *#define SEQ_ARG_PAIRS BOOST_PP_SEQ_TRANSFORM(ARG_PAIR, ~, SEQ_FORMATS)* *#define ARG_PAIRS BOOST_PP_SEQ_ENUM(SEQ_ARG_PAIRS)*

The SEQ_ARG_PAIRS macro does expand into

*({"A", create<AFile>}) ({"B", create<BFile>}) ({"C", create<CFile>})*

but ARG_PAIRS fails with the following error:

test.cpp:20:1: error: macro "BOOST_PP_SEQ_SIZE_0" passed 2 arguments, but takes just 1 ARG_PAIRS ^ BOOST_PP_SEQ_ENUM_0 ({"B", create<BFile>}) ({"C", create<CFile>}) ({"A", create<AFile>}) ({"B", create<BFile>}) ({"C", create<CFile>})

Any ideas?

The reason for this is because after your transformation you do not have a valid seq anymore for BOOST_PP_SEQ_ENUM. Each seq element must be a one element tuple. The comma ( ',' ) in each seq element no longer makes that seq element valid, producing a two element tuple. Something like '({"A", create<AFile>})' really containes two elements of data, the first one being '{"A"' and the second one being 'create<AFile>}'.

thanks a lot

...
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Edward Diener

3:59 p.m.

On 7/7/2016 3:04 AM, Cherotek Music wrote:

...

Thanks I see. I'm at work now and can't test it but would replacing the comma in ARG_PAIR with *BOOST_PP_COMMA help?*

I do not think so.

...

On Thu, Jul 7, 2016 at 1:49 AM, Edward Diener mailto:eldiener@tropicsoft.com> wrote:

On 7/6/2016 5:27 PM, Cherotek Music 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}* *#define SEQ_ARG_PAIRS BOOST_PP_SEQ_TRANSFORM(ARG_PAIR, ~, SEQ_FORMATS)* *#define ARG_PAIRS BOOST_PP_SEQ_ENUM(SEQ_ARG_PAIRS)*

The SEQ_ARG_PAIRS macro does expand into

*({"A", create<AFile>}) ({"B", create<BFile>}) ({"C", create<CFile>})*

but ARG_PAIRS fails with the following error:

test.cpp:20:1: error: macro "BOOST_PP_SEQ_SIZE_0" passed 2 arguments, but takes just 1 ARG_PAIRS ^ BOOST_PP_SEQ_ENUM_0 ({"B", create<BFile>}) ({"C", create<CFile>}) ({"A", create<AFile>}) ({"B", create<BFile>}) ({"C", create<CFile>})

Any ideas?

The reason for this is because after your transformation you do not have a valid seq anymore for BOOST_PP_SEQ_ENUM. Each seq element must be a one element tuple. The comma ( ',' ) in each seq element no longer makes that seq element valid, producing a two element tuple. Something like '({"A", create<AFile>})' really containes two elements of data, the first one being '{"A"' and the second one being 'create<AFile>}'.

thanks a lot

Mathias Gaunard

4:19 p.m.

On 6 July 2016 at 22:27, Cherotek Music 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}* *#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.

Cherotek Music

9:57 p.m.

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} #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} We're getting closer though On Thu, Jul 7, 2016 at 6:19 PM, Mathias Gaunard < mathias.gaunard@ens-lyon.org> wrote:

...

On 6 July 2016 at 22:27, Cherotek Music 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}* *#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.

_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

Cherotek Music

10:05 p.m.

Ah I got it to work with the following: #define SEQ_FORMATS BOOST_PP_VARIADIC_TO_SEQ(FORMATS) #define PASTE(l,r) l##r #define STRINGIZE(x) #x #define ARG_PAIR(x) {STRINGIZE(x), create} #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) Thanks guys! On Thu, Jul 7, 2016 at 11:57 PM, Cherotek Music wrote:

...

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} #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}

We're getting closer though

On Thu, Jul 7, 2016 at 6:19 PM, Mathias Gaunard < mathias.gaunard@ens-lyon.org> wrote:

...
On 6 July 2016 at 22:27, Cherotek Music 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}* *#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.

_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

Edward Diener

8 Jul 8 Jul

12:04 a.m.

On 7/7/2016 6:05 PM, Cherotek Music wrote:

...

Ah I got it to work with the following:

#define SEQ_FORMATS BOOST_PP_VARIADIC_TO_SEQ(FORMATS) #define PASTE(l,r) l##r

BOOST_PP_CAT

...

#define STRINGIZE(x) #x

BOOST_PP_STRINGIZE

...

#define ARG_PAIR(x) {STRINGIZE(x), create} #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)

Thanks guys!

Great !

...

On Thu, Jul 7, 2016 at 11:57 PM, Cherotek Music mailto:cherotek@gmail.com> wrote:

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} #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}

We're getting closer though

On Thu, Jul 7, 2016 at 6:19 PM, Mathias Gaunard mailto:mathias.gaunard@ens-lyon.org> wrote:

On 6 July 2016 at 22:27, Cherotek Music mailto:cherotek@gmail.com> 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}* *#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.

_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org mailto:Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

_______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Cherotek Music
Edward Diener
Mathias Gaunard