rustdoc: --show-coverage shouldn't count tuple struct fields

[taylordotfish]

rustdoc's --show-coverage flag counts public fields of tuple structs, but this doesn't really make sense, since doc attributes on such fields never appear in the generated documentation.

For example, given the following in src/lib.rs:

//! test

/// test
pub struct Test(pub u8);

cargo rustdoc -- -Z unstable-options --show-coverage reports:

+-------------------------------------+------------+------------+------------+------------+
| File                                | Documented | Percentage |   Examples | Percentage |
+-------------------------------------+------------+------------+------------+------------+
| src/lib.rs                          |          2 |      66.7% |          0 |       0.0% |
+-------------------------------------+------------+------------+------------+------------+
| Total                               |          2 |      66.7% |          0 |       0.0% |
+-------------------------------------+------------+------------+------------+------------+

If src/lib.rs is changed to:

//! test

/// test
pub struct Test(
    /// test
    pub u8,
);

then the coverage is reported as 100%, but, as expected, the documentation for the pub u8 field isn't included in the documentation generated by cargo doc.

Meta

rustc 1.52.0-nightly (f5d8117c3 2021-03-16)
binary: rustc
commit-hash: f5d8117c338a788bd24abec733fd143dfceb25a0
commit-date: 2021-03-16
host: powerpc64le-unknown-linux-gnu
release: 1.52.0-nightly
LLVM version: 12.0.0

[camelid]

Tuple struct field docs will be rendered soon, assuming that #80320 merges.

[GuillaumeGomez]

I guess we can now consider this issue to be fixed since #87451 was merged?

[camelid]

@GuillaumeGomez that sounds right to me. Do you want to close it?

[GuillaumeGomez]

Let's close it then. :)