From 3726194fbe3da234eb30b6371e5b4ab1ea388f93 Mon Sep 17 00:00:00 2001 From: jsmall-nvidia Date: Sat, 2 Feb 2019 11:58:54 -0500 Subject: Feature/as refactor review (#821) * Replace dynamicCast with as where does not change behavior (ie not Type derived). Use free function where scoping is clear. * Replace uses of dynamicCast with as when there is no difference in behavior. * Remove the IsXXXX methods from Type. * Don't have separate smart pointer to store canonicalType on Type. * Simplify Slang.FilteredMemberRefList.Adjust, such does the cast directly. * Use free as where appropriate. * Use free function version of casts where appropriate. * Fix text in casting.md * Fix typos in decl-refs.md * Remove the uses of free function as on RefDecl. Add 'canAs' to RefDecl as a way to test if a cast is possible. Moved 'as' into RefDeclBase. * Use 'is' to test for as cast on smart pointers. Fix small scope issue. * * Cache stringType and enumTypeType on the Session * Make DeclRefType::Create return a RefPtr * Make casting of result use the *method* .as (cos using free function would mean objects being wrongly destroyed) * Make results from createInstance ref'd to avoid possible leaks. * Fix typo in template parameter for is on RefPtr. --- docs/design/casting.md | 4 +++- docs/design/decl-refs.md | 4 ++-- 2 files changed, 5 insertions(+), 3 deletions(-) (limited to 'docs') diff --git a/docs/design/casting.md b/docs/design/casting.md index 522e1d707..6c4b119eb 100644 --- a/docs/design/casting.md +++ b/docs/design/casting.md @@ -7,7 +7,7 @@ C++'s built in mechanisms for casting (principally dynamic_cast) is problematic * There are types which we want to 'dynamic_cast' that do not have, and we do not want to have a Vtbl (for example Slang::IRInst). * There are types which a 'dynamic_cast' doesn't do quite what we want (for example casting on Type* derived types typically wants to work on their canonical type) -* We may want to replace use of dynamic_cast in the future for speed/space or other reasons in the future +* We may want to replace use of dynamic_cast in the future for speed/space or other reasons * It is common in the code base when using a 'smart pointer' type to cast it, but still return a smart pointer To deal with these issues we need casting within Slang to follow it's own methodology. In summary it is as follows... @@ -18,6 +18,8 @@ To deal with these issues we need casting within Slang to follow it's own method * If you want to *literally* do a dynamic cast use 'dynamicCast' free function. * This guarantees the returned pointer points to the same object (like normal dynamic_cast) * If you want to return a smart pointer from a cast from a smart pointer use the .as or .dynamicCast *methods* +* If you want to determine if an 'as' cast is possible on a smart pointer use the .is method + * Doing so will produce more efficient code because a new smart pointer does not need to be constructed These functions will also work with types that do not have Vtbl - like IRInst derived types. diff --git a/docs/design/decl-refs.md b/docs/design/decl-refs.md index 1644f6f34..3a84cfdcf 100644 --- a/docs/design/decl-refs.md +++ b/docs/design/decl-refs.md @@ -69,7 +69,7 @@ If we then want to query the type of this field, we can first look up the type s Cell::T [Cell::T => int] ``` -Of course, we can then simplify the reference by applying the substutions, to get: +Of course, we can then simplify the reference by applying the substitutions, to get: ``` int @@ -89,7 +89,7 @@ Each ancestor of a declaration can introduce an expected substitution along the * A surrounding `interface` declaration usually requires a `ThisTypeSubstitution` that identifies the specific type on which an interface member has been looked up. -All of the expected substitutions should be in place in the gerneral case, even when we might not have additional information. E.g., within a generic declaration like this: +All of the expected substitutions should be in place in the general case, even when we might not have additional information. E.g., within a generic declaration like this: ```hlsl struct Cell -- cgit v1.2.3