Add an explicit_type TLV syntax for avoiding certain cases of type inference

[dunxen]

No description provided.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.72%. Comparing base (c7627df) to head (c0d84e8).
Report is 25 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3301      +/-   ##
==========================================
+ Coverage   89.67%   89.72%   +0.04%     
==========================================
  Files         126      126              
  Lines      103165   103747     +582     
  Branches   103165   103747     +582     
==========================================
+ Hits        92510    93083     +573     
- Misses       7935     7949      +14     
+ Partials     2720     2715       -5     

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[dunxen]

I haven't looked for other cases where we can use this syntax to force the type, but if mentioned I can update them in this PR too.

[TheBlueMatt]

New syntax LGTM.

[dunxen]

Edited: Forgot to remove some things. Updated.

git diff-tree -U1 0d7b30d 37e73ca

diff --git a/lightning/src/util/ser_macros.rs b/lightning/src/util/ser_macros.rs
index 3837e3f1..8ebbac10 100644
--- a/lightning/src/util/ser_macros.rs
+++ b/lightning/src/util/ser_macros.rs
@@ -287,3 +287,3 @@ macro_rules! _check_decoded_tlv_order {
 	($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, (required, explicit_type: $fieldty: ty)) => {{
-		// no-op
+		_check_decoded_tlv_order!($last_seen_type, $typ, $type, $field, required);
 	}};
@@ -344,3 +344,3 @@ macro_rules! _check_missing_tlv {
 	($last_seen_type: expr, $type: expr, $field: ident, (required, explicit_type: $fieldty: ty)) => {{
-		// no-op
+		_check_missing_tlv!($last_seen_type, $type, $field, required);
 	}};
@@ -387,6 +387,6 @@ macro_rules! _decode_tlv {
 	($outer_reader: expr, $reader: expr, $field: ident, (option, explicit_type: $fieldty: ty)) => {{
-		$field = Some($crate::util::ser::Readable::read(&mut $reader)?);
+		let field: $fieldty = _decode_tlv!($outer_reader, $reader, $field, option); $field = Some(field);
 	}};
 	($outer_reader: expr, $reader: expr, $field: ident, (required, explicit_type: $fieldty: ty)) => {{
-		$field = Some($crate::util::ser::Readable::read(&mut $reader)?);
+		let field: $fieldty = _decode_tlv!($outer_reader, $reader, $field, required); $field = field;
 	}};

[TheBlueMatt]

Thanks, this is gonna be really nice to use. Pretty straightforward so just gonna land it.