centos7でsassc 2.0.0 with native extensionsのインストールに失敗

bundleに失敗するから、sasscだけ単独でインストールしてみた所、以下のエラーが発生。

$ gem install sassc -v '2.0.0' --source 'https://rubygems.org/'
Building native extensions. This could take a while...
ERROR:  Error installing sassc:
	ERROR: Failed to build gem native extension.

    current directory: /home/foo/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/sassc-2.0.0/ext
/home/foo/.rbenv/versions/2.5.3/bin/ruby -rrubygems /home/foo/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/rake-12.3.1/exe/rake RUBYARCHDIR=/home/foo/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/extensions/x86_64-linux/2.5.0-static/sassc-2.0.0 RUBYLIBDIR=/home/foo/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/extensions/x86_64-linux/2.5.0-static/sassc-2.0.0
cd libsass
make lib/libsass.so
mkdir lib
cc -Wall -O2 -I /home/foo/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/sassc-2.0.0/ext/libsass/include -fPIC -fPIC -c -o src/cencode.o src/cencode.c
src/cencode.c: 関数 ‘base64_encode_block’ 内:
src/cencode.c:50:5: 警告: 空の宣言です [デフォルトで有効]
     __attribute__ ((fallthrough));
     ^
src/cencode.c:64:5: 警告: 空の宣言です [デフォルトで有効]
     __attribute__ ((fallthrough));
     ^
g++ -Wall -O2 -std=c++0x -I /home/foo/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/sassc-2.0.0/ext/libsass/include -fPIC -fPIC -c -o src/ast.o src/ast.cpp
make: g++: コマンドが見つかりませんでした
make: *** [src/ast.o] エラー 127
rake aborted!
Command failed with status (2): [make lib/libsass.so...]

Tasks: TOP => lib/libsass.so
(See full trace by running task with --trace)

rake failed, exit code 1

Gem files will remain installed in /home/foo/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/sassc-2.0.0 for inspection.
Results logged to /home/foo/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/extensions/x86_64-linux/2.5.0-static/sassc-2.0.0/gem_make.out

gcc-c++が足りていないだけ。

$ sudo yum install gcc-c++

あらためてインストールし、成功

$ gem install sassc -v '2.0.0' --source 'https://rubygems.org/' 
Building native extensions. This could take a while...
Successfully installed sassc-2.0.0
Parsing documentation for sassc-2.0.0
Installing ri documentation for sassc-2.0.0
Done installing documentation for sassc after 4 seconds
1 gem installed