Thanks for the fixes. Which release of boost will this be available in? Will we have to wait for a 1.67 or can we get it in a hotfix 1.66.1?

IMO, 1.66.1 is highly unlikely since 1.67 is on the way. I would hope someone with permissions will be able to merge it to develop and then to master before 1.67 is out, but no guarantees on that.

This doesn't work with toolchains 21, 22 and 23, failing with error:

C:\Android\toolchain21\bin/../lib/gcc/arm-linux-androideabi/4.9.x/../../../../include/c++/4.9.x\cstdio:107:11: error: no member named 'fgetpos' in the global namespace
  using ::fgetpos;
        ~~^
C:\Android\toolchain21\bin/../lib/gcc/arm-linux-androideabi/4.9.x/../../../../include/c++/4.9.x\cstdio:117:11: error: no member named 'fsetpos' in the global namespace
  using ::fsetpos;
        ~~^
2 errors generated.

Changing the guard to __ANDROID_API__ < 24 fixes this.

See also this documentation that mentions API 24 is the first API that has all functions included in <stdio.h>.

@MaartenBent, thanks for the heads up.

The issue with fgetpos and fsetpos seems to be this one: android/ndk#480 . Android NDK developers fixed it in r16 with this patch: https://android.googlesource.com/platform/ndk/+/d5acdb0ee5ad536d543b509d83cfa79b9d01b3b1 , but only for libc++. I think, they did it as an exception, because compilation failure on just #include <cstdio> is really ridiculous. They refuse to fix it for gnustl, because they are deprecating gnustl in favor of libc++.

It means that the issue still exists for Android APIs 21-23 on:

• NDK r16 and above with gnustl.
• NDK r14 and r15 with any STL and enabled Unified Headers.

@MaartenBent, judging from you error messages, you are using gnustl.

@MaartenBent, I agree, it's better to change the guard to __ANDROID_API__ < 24. I will update the pull request.

It's possible to get 64-bit truncate for APIs 21-23, but it seems to require some complicated logic. I am not sure it's worth the hassle. And I don't want to further complicate and delay the review of this pull request. If anyone needs 64-bit truncate particularly for API range 21-23, I think he/she should make it as a separate pull request.

It compiles with android API level 19 and the verification if the file is not to big for resizing does indeed looks like a good fix, so I can execute my App on an Android with a higher API level (with 64-Bit support).

With the last change, is this really sure that this is compiling with gnustl and API level 24? And when I check the Roadmap from Android they planned:

NDK r17
Estimated release: Q1 2018
Default to libc++

NDK r18
Estimated release: Q2 2018
Remove non-libc++ STLs
Remove GCC

So Q2/2018 it's not far away... gnustl will be removed.
Maybe you add another check which STL libraries is used like
(__ANDROID_API__ < 21 && _LIBCPP_VERSION) || (__ANDROID_API__ < 24 && __GLIBCXX__)
or something like that. See also Pre-defined C/C++ Compiler Macros
Btw ... should I close #65 ?

With the last change, is this really sure that this is compiling with gnustl and API level 24

For me it compiles successfully with API 21 and API 24. I do not define the stl when creating the toolchain so gnustl is used as default.

Maybe you add another check which STL libraries is used like

This doesn't work because __GLIBCXX__ is not yet defined, from your link:

One of the standard header files must be included before any of the following macros are defined.

After moving #include <cstdlib> to the beginning of the file it works. I did not check if _LIBCPP_VERSION is defined correctly when using libc++, or if moving the include has any side effects.

After you included a system header, it's already too late to define _FILE_OFFSET_BITS.

Btw ... should I close #65 ?

@Bjoe: No, of course not. First, you have very good description of the issue. With relevant error messages and code snippets. Second, if you close the issue - it may confuse people, someone may get an idea that the issue is fixed.

Dear Boost.Filesystem maintainers, @Beman and @pdimov.

I submitted this pull request several days ago. How can I get it reviewed?

Congratulations with the International Space Day, everyone. According to the Git logs, @Beman was on Earth 2 days ago and made some commits to the repository.

On this nice day, can I ask @Beman for some attention to this pull request?

This pull request is waiting for review 2 months already.

@Beman , @pdimov : Boost 1.67 is out, maybe now you have time to review and merge the patch?

Maybe you see some issue in the patch? And have suggestion for improvement?

Looks good to me. If @Beman doesn't object, I'll merge that in a few days.

Hurrah! :) Thanks for the merging!