Create LDM-2019-08-26.md

meetings/2019/LDM-2019-08-26.md

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+# C# Language Design Notes for Aug 26, 2019
+
+## Agenda
+
+Triage of newly championed issues. Features that we may consider are placed in the milestone where we will look at them again. Listed here by target milestone.
+
+# Milestone 8.X
+
+We are unsure if there will be an 8.1 release or we will go straight to C# 9.0. In the latter case we will triage this bucket and move things to 9.0 or later.
+
+## #883 Zero and one-element tuples
+
+We don't have a good syntax for one-tuples.
+
+But in deconstruction and pattern matching there is less of a syntax problem.
+
+What does `(3)` mean? It is a constant 3. If you want a tuple literal, you can just give it a name - that is unambiguous. `(_: 3)` might become the common pattern, though `_` isn't a discard for tuple element names.
+
+Could consider splitting the feature and doing only one-element tuples in literals and deconstruction.
+
+
+# Milestone 9.0
+
+This is the next major release (as C# 8.0 is a done deal at this point). Putting features in this milestone doesn't mean that we will do them here! It just means that we will consider them in this timeframe - possibly to be rejected or pushed out at that point.
+
+## #146
+
+There's something to this, but instead of marking seperately, we think it is paired with allowing nullary constructors on structs . For those we would warn on uses of `default(S)` that we can detect, similar to nullability.
+
+## #812
+
+Could work with conjunctive patterns. An alternative would be a range-like syntax.
+
+## #1792, #1793, #1502
+
+Let's keep ironing out annoying limitations in this space
+
+## #1881
+
+Should think also of UTF8
+
+For `Memory<char>` etc we would probably continue to require you to go through `Span<char>` etc.
+
+## #2585
+
+Fits well with a "math" push, and should align with that.
+
+
+# Milestone X.0
+
+These would be major features, and we don't expect to consider them for C# 9.0.
+
+## #339
+
+This is a very fundamental feature, and we're not sure we have compelling scenarios. Possibly the next thing to look at after "type classes" in the advanced type features category.
+
+## #1047
+
+This is probably in pattern matching's future somewhere, though we won't be ready for it in 9.0.
+
+## #538
+
+Probably requires runtime work, and the scenarios don't currently justify that.
+
+## #2545 (Blocked)
+
+We keep not moving on this. We'd need a good understanding with EF
+
+
+# Milestone X.X
+
+These would be minor features which we don't expect to consider until after 9.0.
+
+## #2608
+
+Fine, but doesn't rise to priority
+
+
+# Rejected
+
+## #301
+
+This is subsumed by "extension everything" and the other proposals in that ilk. We do understand and support the scenario, but don't want the specific feature.
+
+## #1033
+
+Rejected. The assignment should happen explicitly in the body, and the compiler can warn if you forget.
+
+## #1586
+
+It shipped and it's in unsafe. We're ok with it.
+
+
+
+## #2383
+
+The language is what it is at this point, and it is not worth doing work to "fix" it. However we should add a warning wave warning on the initializers saying they won't ever be called.
+
+
+
+
+