Simple sample project demonstrating Hunter boost flags problem
Usage:
mkdir -p build-osx-10-7; cd build-osx-10-7
POLLY_DIR="$(cd ../polly && pwd)"
XCODE_XCCONFIG_FILE="${POLLY_DIR}"/scripts/NoCodeSign.xcconfig \
cmake -G Xcode -DCMAKE_TOOLCHAIN_FILE="${POLLY_DIR}"/osx-10-7.cmake ..
or
mkdir -p build-ios-6-1; cd build-ios-6-1
POLLY_DIR="$(cd ../polly && pwd)"
XCODE_XCCONFIG_FILE="${POLLY_DIR}"/scripts/NoCodeSign.xcconfig \
cmake -G Xcode -DCMAKE_TOOLCHAIN_FILE="${POLLY_DIR}"/ios-nocodesign-6-1-armv7.cmake ..
Both cases not only fail to propagate -stdlib=libc++, but also flags such
as -fvisibility -ffunction-sections and -fdata-sections. It's clear from
the Hunter-generated boost.user.jam
Failing to propagate -stdlib manifests as:
In file included from ./boost/config.hpp:44:
./boost/config/detail/select_stdlib_config.hpp:18:12: fatal error: 'cstddef' file not found
# include <cstddef>
The fatal error does not happen when targeting OS X 10.8 / iOS 7 or above, because in
those cases clang defaults to -stdlib=libc++. Failing to pass the other flags
happens on all targets though.
The problem seems to go away when switching from Xcode to Makefiles. Test case:
mkdir build-osx-10-7-makefiles; cd build-osx-10-7-makefiles
POLLY_DIR="$(cd ../polly && pwd)"
cmake -G "Unix Makefiles" -DCMAKE_TOOLCHAIN_FILE="${POLLY_DIR}"/osx-10-7-makefiles.cmake ..
And then all the requested flags make their way into boost.user.jam and Boost::chrono builds properly.
Switching to Makefiles does not appear to be an option for iOS + Polly though.