error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
  --> $DIR/not-an-allocator.rs:2:1
   |
LL | #[global_allocator]
   | ------------------- in this procedural macro expansion
LL | static A: usize = 0;
   | ^^^^^^^^^^^^^^^^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
   |
note: required by `std::alloc::GlobalAlloc::alloc`
  --> $SRC_DIR/core/src/alloc/global.rs:LL:COL
   |
LL |     unsafe fn alloc(&self, layout: Layout) -> *mut u8;
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: this error originates in the attribute macro `global_allocator` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
  --> $DIR/not-an-allocator.rs:2:1
   |
LL | #[global_allocator]
   | ------------------- in this procedural macro expansion
LL | static A: usize = 0;
   | ^^^^^^^^^^^^^^^^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
   |
note: required by `std::alloc::GlobalAlloc::dealloc`
  --> $SRC_DIR/core/src/alloc/global.rs:LL:COL
   |
LL |     unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout);
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: this error originates in the attribute macro `global_allocator` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
  --> $DIR/not-an-allocator.rs:2:1
   |
LL | #[global_allocator]
   | ------------------- in this procedural macro expansion
LL | static A: usize = 0;
   | ^^^^^^^^^^^^^^^^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
   |
note: required by `std::alloc::GlobalAlloc::realloc`
  --> $SRC_DIR/core/src/alloc/global.rs:LL:COL
   |
LL |     unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: this error originates in the attribute macro `global_allocator` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0277]: the trait bound `usize: GlobalAlloc` is not satisfied
  --> $DIR/not-an-allocator.rs:2:1
   |
LL | #[global_allocator]
   | ------------------- in this procedural macro expansion
LL | static A: usize = 0;
   | ^^^^^^^^^^^^^^^^^^^^ the trait `GlobalAlloc` is not implemented for `usize`
   |
note: required by `std::alloc::GlobalAlloc::alloc_zeroed`
  --> $SRC_DIR/core/src/alloc/global.rs:LL:COL
   |
LL |     unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = note: this error originates in the attribute macro `global_allocator` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 4 previous errors

For more information about this error, try `rustc --explain E0277`.