os_ver

Macro if_greater_than

Source 
macro_rules! if_greater_than {
    {($major:expr) => $block:block $(else $else_block:block)?} => { ... };
    {($major:expr, $minor:expr) => $block:block $(else $else_block:block)?} => { ... };
    {($major:expr, $minor:expr, $patch:expr) => $block:block $(else $else_block:block)?} => { ... };
    {($major:expr, $minor:expr, $patch:expr, $build:expr) => $block:block $(else $else_block:block)?} => { ... };
    {$version:expr => $block:block $(else $else_block:block)?} => { ... };
}