error[E0408]: variable `b` is not bound in all patterns
  --> $DIR/issue-39698.rs:10:9
   |
LL |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |         ^^^^^^^^^^^            -    ^^^^^^^^   ^^^^^^^^ pattern doesn't bind `b`
   |         |                      |    |
   |         |                      |    pattern doesn't bind `b`
   |         |                      variable not in all patterns
   |         pattern doesn't bind `b`

error[E0408]: variable `c` is not bound in all patterns
  --> $DIR/issue-39698.rs:10:9
   |
LL |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |         ^^^^^^^^^^^   ^^^^^^^^^^^         -    ^^^^^^^^ pattern doesn't bind `c`
   |         |             |                   |
   |         |             |                   variable not in all patterns
   |         |             pattern doesn't bind `c`
   |         pattern doesn't bind `c`

error[E0408]: variable `a` is not bound in all patterns
  --> $DIR/issue-39698.rs:10:23
   |
LL |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |               -       ^^^^^^^^^^^   ^^^^^^^^         - variable not in all patterns
   |               |       |             |
   |               |       |             pattern doesn't bind `a`
   |               |       pattern doesn't bind `a`
   |               variable not in all patterns

error[E0408]: variable `d` is not bound in all patterns
  --> $DIR/issue-39698.rs:10:37
   |
LL |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |                  -          -       ^^^^^^^^   ^^^^^^^^ pattern doesn't bind `d`
   |                  |          |       |
   |                  |          |       pattern doesn't bind `d`
   |                  |          variable not in all patterns
   |                  variable not in all patterns

error[E0381]: used binding `a` is possibly-uninitialized
  --> $DIR/issue-39698.rs:10:79
   |
LL |         T::T1(a, d) | T::T2(d, b) | T::T3(c) | T::T4(a) => { println!("{:?}", a); }
   |               -                                      -                        ^ `a` used here but it is possibly-uninitialized
   |               |                                      |
   |               |                                      binding initialized here in some conditions
   |               binding initialized here in some conditions
   |               binding declared here but left uninitialized
   |
   = note: this error originates in the macro `$crate::format_args_nl` which comes from the expansion of the macro `println` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 5 previous errors

Some errors have detailed explanations: E0381, E0408.
For more information about an error, try `rustc --explain E0381`.