Build error on Android NDK 25

[raidenluikang]

@trueqbit

I just download sqlite_orm.h file from following url

https://github.com/FireDaemon/sqlite_orm/tree/issues/no-rtti

And got an error:

sqlite_orm.h:7938:24: error: no member named 'identity' in namespace 'std' using std::identity;

I'm building for android with NDK 25. -std=c++20 mode. clang 14, but there libc++ is not implemented std::identity.

Could you fix it?

Thanks.

EDIT: And there also not compiling call storage.pragma.foreign_keys() function. Can't find pragma.foreign_keys() function.

[trueqbit]

What is the version of libc++ that comes with the NDK? The Android documentation says that LLVM libc++ is included, and it specifically refers to the progress of the C++20 library implementation of libc++. On the latter page, the line "The identity metafunction" states that it has already been implemented in libc++ v8.

[raidenluikang]

I couldn't find std::identity in $HOME/Android/Sdk/ndk/25.1.8937393/sources/cxx-stl/llvm-libc++/include folder.

raiden:include$ pwd
/home/raiden/Android/Sdk/ndk/25.1.8937393/sources/cxx-stl/llvm-libc++/include

raiden:include$ grep -rn "\btype_identity\b" .
./type_traits:77:    template<class T> struct type_identity;                     // C++20
./type_traits:79:      using type_identity_t = typename type_identity<T>::type;  // C++20
./type_traits:1473:// type_identity
./type_traits:1475:template<class _Tp> struct type_identity { typedef _Tp type; };
./type_traits:1476:template<class _Tp> using type_identity_t = typename type_identity<_Tp>::type;

raiden:include$ grep -rn "\bidentity\b" .
raiden:include$ 
raiden:include$ 

In other side.

https://libcxx.llvm.org/Status/Cxx20.html

indicates P0887R1 - which about std::type_identity ,

not about std::identity ).

[trueqbit]

My mistake - you are correct that it is std::type_identity.
std::identity came with libcxx 13.

So, what is your version of libcxx (possibly using the macro _LIBCPP_VERSION)?

[raidenluikang]

raiden:include$ grep -rn "_LIBCPP_VERSION" .
./__config:35:#define _LIBCPP_VERSION 11000
./version:10:#ifndef _LIBCPP_VERSIONH
./version:11:#define _LIBCPP_VERSIONH
./version:241:#endif // _LIBCPP_VERSIONH
raiden:include$ pwd
/home/raiden/Android/Sdk/ndk/25.1.8937393/sources/cxx-stl/llvm-libc++/include
raiden:include$ 

[trueqbit]

Thanks for the information!

It's strange that the Android NDK would use Clang 14, but an old version of libc++.
Anyway, if you could try the branch linked to PR #1140 and let us know how it goes.

[raidenluikang]

How about storage.execute_raw("PRAGMA user_version = 1;") and storage.pragma.foreign_keys(true) functions, I couldn't find they ( execute_raw and foreign_key) in no rtti version of sqlite_orm.h file ?

How I could to fix they?

Thanks.

[fnc12]

storage.user_version(1);

Foreign keys are enabled by default if your schema has at least one FK

[raidenluikang]

Thanks.

Last one, how about storage.execute_tables_from_master_table ?
it was removed ?

[fnc12]

what does storage.execute_tables_from_master_table mean?

[raidenluikang]

what does storage.execute_tables_from_master_table mean?

Sorry, It turns out that this was our function, written sqlite_orm.h). Executes

"select sql from sqlite_master where type = 'table' order by tbl_name asc" query.

---

Can select that sqlite_master table with standard functionality of storage?

Likely, this table https://www.sqlite.org/schematab.html

[fnc12]

the only way to interact with sqlite_master is storage.table_names() which calls SELECT name FROM sqlite_master WHERE type='table'. Why do you need sqlite_master.sql?

[trueqbit]

Request for sqlite_master to be followed up in #1142.