error: reinterpret_cast from type ‘const char*’ to type ‘Bytef* {aka unsigned char*}’ casts away qualifiers

[AKJ7]

The solution is to look for line with reinterpreted_cast<z_const Bytef*>(data) to reinterpreted_cast<z_const Bytef*>(&data) for example. This needs to be done twice. Once in the compress.hpp and the decompress.hpp.

[springmeyer]

@AKJ7 - could you share what compiler you hit this error with?

[AKJ7]

@springmeyer , thanks for the reply, but i had this issue a long time ago and ended up written my own gzip library.

[gordinmitya]

May I reopen the issue?
the same error on the same line
I'm trying to compile in android project with CMake
What information I can provide in order to help you?

[springmeyer]

@gordinmitya please paste the entire compile error, including the compiler command with all the arguments passed to the compiler. Please also provide the C++ compiler version.

[springmeyer]

And also, if you can please provide the zlib.h version on your system.

[springmeyer]

The problem is likely that your zlib install is too old and does not support the ZLIB_CONST compiler define.

[gordinmitya]

Thank you for your super fast response!
your suggestion about version of zlib led me to explicitly specify it in CMakeLists.txt:

find_package(ZLIB REQUIRED)
target_include_directories(mylib PRIVATE ${ZLIB_INCLUDE_DIRS})
target_link_libraries(mylib ${ZLIB_LIBRARIES})

(it tried to compile without that, don't now how).

Now it successfully compiles and works on Android (armeabi-v7a and arm64-v8a).

Thank you for your time!

MacOS 10.15.3, ZLIB_VERSION "1.2.7", Android NDK 21.0.6113669

[psy0rz]

I also struggled with this quite a while:

The problem is something else already included zlib.h, so that the ZLIB_CONST define has no effect.

Try defining it before anything else gets compiled, for example in your CMakeList.txt:

add_definitions(-D ZLIB_CONST )

[rmcolq]

This is an old issue, but I ran into the same error on a MacM1 using a modern brew-installed gcc compiler and adding this definition to my CMakeList.txt solved it for me