tree b7894f9d599125ea11cd3f10a2cdf713262a14bb
parent 8e54a6e9e17eb484184ddbdfd9d1b530acd5b40e
author John Stiles <johnstiles@google.com> 1597757040 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> 1597759455 +0000

Add as<ExpressionSubclass>() to downcast Expressions more safely.

The as<T>() function asserts that the Expression is of the correct kind
before performing the downcast, and is also generally easier to read
as function calls flow naturally from left-to-right, and C-style casts
don't.

This CL updates several Expression downcasts in SkSL to the as<T>
syntax, but is not intended to exhaustively replace them all (although
that would be ideal). In places where we SkASSERTed the expression's
fKind immediately before a cast, the assert has been removed because it
would be redundant with the behavior of as<T>().

Change-Id: I67e7de2697aee4d9d09e6594a9abc5f2ecacc887
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/311114
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>