This gives users the control over where clap outputs while still getting
colors. For users who want to support old windows versions, check out
`fwdansi` crate.
The writer is less convenient and isn't offering any performance
benefits of avoidign the extra allocations, so let's render instead.
This supersedes #3874Fixes#3873
Things that tripped up a user
- Derive reference was misunderstood to say that the only alternative to
the built-in value parser behavior was to implement
`ValueParserFactory`
- We now delegate to `value_parser!`s docs any talk of integrating
into it (it should have been a subbullet of "not present" anyways)
- `value_parser!` relies too much on the example to demonstrate behavior
when the user will likely make the determination of whether its
relevant before then
- We are now more upfront what type mappings are supported
- Too many steps to find all information
- For example, a user needs to look at `TypedValueParser`
implementations, `ValueParserFactory` implementations, and `From<T>
for ValueParser` implementations to understand what all can be used
- We are now more upfront with a lot of this information at the entry
points the user is most likely to look at
In addition, I did an audit of the docs to make sure they were updated
for us only supporting the new behavior and all of the new APIs.
See https://www.reddit.com/r/rust/comments/xjlie4/preannouncing_clap_40_a_rust_cli_argument_parser/ip9kzf1/
`clap::Error::raw` was producing ambiguity errors with a default generic
parameter on `clap::error::Error` (which `clap::Error` is a re-export
of).
I tried making `clap::Error` a type alias with a default generic
parameter but that ran into an ambiguity error with `map_err`.
So I'm going ahead and hard coding `clap::Error`. We don't expect
people to change this all that often.
This takes off another 14 KiB when color us not used. My hope is that
we'll be able to switch away from `termcolor` to a term styling crate
that will make this work in the color case as well.
This is a cheap pass at creating this to allow cutting out the cost of
rich error information / programmatic error information.
This cuts about 20 KiB off of the binary.
There is more we could cut out, like collecting of used arguments for
the usage, but I want to keep the conditionals simple.
