Use two different Versions of boost - c++

Question

i try to build a cmake which use two different version of boost. ( I use a framework which only runs with boost 1.55 but my application needs boost 1.57)
My idea was to make 2 Cmake build processes
Application Cmake boost 1.57
cmake_minimum_required (VERSION 2.6)
project (Application)
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fdiagnostics-color=auto -std=c++0x ")
set(Boost_DEBUG ON)
set(Boost_NO_SYSTEM_PATHS TRUE)
set(BOOST_ROOT /opt/boost/boost_1_57)
find_package(Boost 1.57 REQUIRED COMPONENTS thread filesystem log system)
include_directories(
${CMAKE_CURRENT_SOURCE_DIR}
SYSTEM /opt/boost/boost_1_57/include
)
ADD_LIBRARY( AppLib SHARED testVersion.cpp ...)
Framework Cmake boost 1.55
cmake_minimum_required(VERSION 2.8.3)
project(Test)
add_subdirectory(Application)
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fdiagnostics-color=auto -std=c++0x ")
set(Boost_NO_SYSTEM_PATHS TRUE)
set(BOOST_ROOT $ENV{BOOST_ROOT})
find_package(Boost 1.55 REQUIRED COMPONENTS thread filesystem log system)
include_directories(
SYSTEM ${Boost_INCLUDE_DIRS}
)
add_executable(test test.cpp)
target_link_libraries( test AppLib )
test.cpp
#include "testVersion.hpp"
int main() {
std::cout << "Main call Using Boost "
<< BOOST_VERSION / 100000 << "." // major version
<< BOOST_VERSION / 100 % 1000 << "." // minior version
<< BOOST_VERSION % 100 // patch level
<< std::endl;
std::cout << "library : " << std::endl;
Version v;
v.callVersion();
}
testVersion
#include "testVersion.hpp"
void Version::callVersion()
{ std::cout << "Using Boost "
<< BOOST_VERSION / 100000 << "." // major version
<< BOOST_VERSION / 100 % 1000 << "." // minior version
<< BOOST_VERSION % 100 // patch level
<< std::endl;
}
testVersion.hpp
#include <boost/version.hpp>
class Version
{
public:
void callVersion();
};
If i do it this way it runs well :
Output:
Main call Using Boost 1.55.0
Using Boost 1.57.0
But when I eliminate the testVersion.cpp file and inline my callVersion I get the output:
Main call Using Boost 1.55.0
library :
Using Boost 1.55.0
because the compiler use for the headers boost 1.55 only when i include boost in the source files he takes 1.57. How i can solve that ? is that possible?
Conclusion:
I need an empty header :
all_boost_includes.hpp
with a all_boost_includes.cpp
#include "boost..."
#include ...
which will just include all boost headers. And then i have to include this header in every header in my application. Is that correct?
This is similar to an precompiled boost header or?
I tried include "boost_headers.hpp" which is empty and has a boost_header.cpp which includes boost versions
I added on my Application cmake
ADD_LIBRARY( AppLib SHARED boost_headers.cpp)
But when i try
#include "precompiled_boost.hpp"
#include <fstream>
#include <iostream>
class Version
{
public:
void callVersion(){
std::cout << "Using Boost "
<< BOOST_VERSION / 100000 << "." // major version
<< BOOST_VERSION / 100 % 1000 << "." // minior version
<< BOOST_VERSION % 100 // patch level
<< std::endl;
}
};
He don't know BOOST_VERSION. What I have to do there ? If i include precompiled_boost.cpp i get the wrong output

Answer 1

1. If you do not inline callVersion
Compiling library compiles code for Version::callVersion within the library. As library uses boost 1.55 Version::callVersion will return 1.55.
2. If you do inline callVersion
Compiling library does not compile code for Version::callVersion within the library, because it will bi inlined! Your Version::callVersion will actually be compiled on the test side. As test uses boost 1.57, Version::callVersion will return 1.57
Conclusion
You should not inline you calls. More, you cannot use classes that refer to any boost in their declarations in both application and library projects that use different versions of boost. If you have to, you should consider creating some proxy objects or functions, so all boost stuff will be encapsulated inside your library.