error: Unnecessary nested match
  --> $DIR/collapsible_match2.rs:8:34
   |
LL |               Ok(val) if make() => match val {
   |  __________________________________^
LL | |                 Some(n) => foo(n),
LL | |                 _ => return,
LL | |             },
   | |_____________^
   |
   = note: `-D clippy::collapsible-match` implied by `-D warnings`
help: The outer pattern can be modified to include the inner pattern.
  --> $DIR/collapsible_match2.rs:8:16
   |
LL |             Ok(val) if make() => match val {
   |                ^^^ Replace this binding
LL |                 Some(n) => foo(n),
   |                 ^^^^^^^ with this pattern

error: Unnecessary nested match
  --> $DIR/collapsible_match2.rs:15:24
   |
LL |               Ok(val) => match val {
   |  ________________________^
LL | |                 Some(n) => foo(n),
LL | |                 _ => return,
LL | |             },
   | |_____________^
   |
help: The outer pattern can be modified to include the inner pattern.
  --> $DIR/collapsible_match2.rs:15:16
   |
LL |             Ok(val) => match val {
   |                ^^^ Replace this binding
LL |                 Some(n) => foo(n),
   |                 ^^^^^^^ with this pattern

error: Unnecessary nested match
  --> $DIR/collapsible_match2.rs:29:29
   |
LL |                       $pat => match $e {
   |  _____________________________^
LL | |                         $inner_pat => $then,
LL | |                         _ => return,
LL | |                     },
   | |_____________________^
...
LL |           mac!(res_opt => Ok(val), val => Some(n), foo(n));
   |           ------------------------------------------------- in this macro invocation
   |
help: The outer pattern can be modified to include the inner pattern.
  --> $DIR/collapsible_match2.rs:41:28
   |
LL |         mac!(res_opt => Ok(val), val => Some(n), foo(n));
   |                            ^^^          ^^^^^^^ with this pattern
   |                            |
   |                            Replace this binding
   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 3 previous errors