سلام وقتی دستور sudo apt-get install g++-4.9 رو مینویسم ارور زیر رو میده
ممنون میشم راهنمایی کنید چیکار کنم.
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package g++-4.9 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'g++-4.9' has no installation candidate