still trying to get llvm builds under linux on travis to run
diff --git a/.travis.yml b/.travis.yml
index 530981a..8e2bf39 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,5 @@
+# this file is HEAVILY influenced by https://github.com/boostorg/hana/blob/master/.travis.yml
+
 sudo: false
 language: c++
 
@@ -300,12 +302,43 @@
 install:
   - DEPS_DIR="${TRAVIS_BUILD_DIR}/deps"
   - mkdir ${DEPS_DIR} && cd ${DEPS_DIR}
+
+  ############################################################################
+  # Install Clang
+  ############################################################################
   - |
     if [[ "${LLVM_VERSION}" != "" ]]; then
       CLANG_URL="http://llvm.org/releases/${LLVM_VERSION}/clang+llvm-${LLVM_VERSION}-x86_64-linux-gnu-ubuntu-14.04.tar.xz"
       mkdir clang && travis_retry wget --quiet -O - ${CLANG_URL} | tar --strip-components=1 -xJ -C clang
       export PATH="${DEPS_DIR}/clang/bin:${PATH}"
     fi
+  ############################################################################
+  # Install libc++ and libc++abi (on Linux only; Xcode uses libc++ by default)
+  ############################################################################
+  - |
+    if [[ "${LLVM_VERSION}" != "" ]]; then
+      if [[ "${LLVM_VERSION}" != "trunk" ]]; then
+        LLVM_URL="http://llvm.org/releases/${LLVM_VERSION}/llvm-${LLVM_VERSION}.src.tar.xz"
+        LIBCXX_URL="http://llvm.org/releases/${LLVM_VERSION}/libcxx-${LLVM_VERSION}.src.tar.xz"
+        LIBCXXABI_URL="http://llvm.org/releases/${LLVM_VERSION}/libcxxabi-${LLVM_VERSION}.src.tar.xz"
+        TAR_FLAGS="-xJ"
+      else
+        LLVM_URL="https://github.com/llvm-mirror/llvm/archive/master.tar.gz"
+        LIBCXX_URL="https://github.com/llvm-mirror/libcxx/archive/master.tar.gz"
+        LIBCXXABI_URL="https://github.com/llvm-mirror/libcxxabi/archive/master.tar.gz"
+        TAR_FLAGS="-xz"
+      fi
+      mkdir -p llvm llvm/build llvm/projects/libcxx llvm/projects/libcxxabi
+      travis_retry wget --quiet -O - ${LLVM_URL} | tar --strip-components=1 ${TAR_FLAGS} -C llvm
+      travis_retry wget --quiet -O - ${LIBCXX_URL} | tar --strip-components=1 ${TAR_FLAGS} -C llvm/projects/libcxx
+      travis_retry wget --quiet -O - ${LIBCXXABI_URL} | tar --strip-components=1 ${TAR_FLAGS} -C llvm/projects/libcxxabi
+      (cd llvm/build && cmake .. -DCMAKE_INSTALL_PREFIX=${DEPS_DIR}/llvm/install -DCMAKE_CXX_COMPILER=clang++)
+      (cd llvm/build/projects/libcxx && make install -j2)
+      (cd llvm/build/projects/libcxxabi && make install -j2)
+      export CXXFLAGS="-nostdinc++ -isystem ${DEPS_DIR}/llvm/install/include/c++/v1"
+      export LDFLAGS="-L ${DEPS_DIR}/llvm/install/lib -l c++ -l c++abi"
+      export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:${DEPS_DIR}/llvm/install/lib"
+    fi
 #  - export CXX="ccache ${COMPILER}"
   - export CXX="${COMPILER}"
 #  - ccache -s