Bump MSRV to Rust 1.63.0

As we have done in `rust-bitcoin` bump the MSVR to Rust 1.63.0

While we are at it and so that the commit lints cleanly fix a couple of
new clippy warnings:

- Remove redundant import of `TryFrom`
- Use `then_some` combinator

Author: tcharding

.github/workflows/rust.yml

@@ -54,7 +54,7 @@ jobs:
         run: ./maintainer-tools/ci/run_task.sh nightly
 
   MSRV:                         # 1 jobs, minimal lock file only.
-    name: Test - 1.56.1 toolchain
+    name: Test - 1.63.0 toolchain
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -71,7 +71,7 @@ jobs:
       - name: "Select toolchain"
         uses: dtolnay/rust-toolchain@stable
         with:
-          toolchain: "1.56.1"
+          toolchain: "1.63.0"
       - name: "Set dependencies"
         run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
       - name: "Run test script"

Cargo.toml

@@ -8,7 +8,8 @@ repository = "https://github.com/rust-bitcoin/rust-miniscript/"
 description = "Miniscript: a subset of Bitcoin Script designed for analysis"
 keywords = [ "crypto", "bitcoin", "miniscript", "script" ]
 readme = "README.md"
-edition = "2018"
+edition = "2021"
+rust-version = "1.63.0"
 
 [features]
 default = ["std"]

README.md

@@ -1,6 +1,6 @@
 ![Build](https://github.com/rust-bitcoin/rust-miniscript/workflows/Continuous%20integration/badge.svg)
 
-**Minimum Supported Rust Version:** 1.56.1
+**Minimum Supported Rust Version:** 1.63.0
 
 # Miniscript
 
@@ -41,7 +41,7 @@ Enabling the `no-std` feature does not disable `std`. To disable the `std` featu
 
 ## Minimum Supported Rust Version (MSRV)
 
-This library should always compile with any combination of features on **Rust 1.56.1**.
+This library should always compile with any combination of features on **Rust 1.63.0**.
 
 Some dependencies do not play nicely with our MSRV, if you are running the tests
 you may need to pin some dependencies. See `./contrib/test.sh` for current pinning.

clippy.toml

@@ -1,3 +1,3 @@
-msrv = "1.56.1"
+msrv = "1.63.0"
 # plan API returns Self as an error type for an large-ish enum
 large-error-threshold = 256

fuzz/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "descriptor-fuzz"
 edition = "2021"
-rust-version = "1.56.1"
+rust-version = "1.63.0"
 version = "0.0.1"
 authors = ["Generated by fuzz/generate-files.sh"]
 publish = false

fuzz/generate-files.sh

@@ -13,7 +13,7 @@ cat > "$REPO_DIR/fuzz/Cargo.toml" <<EOF
 [package]
 name = "descriptor-fuzz"
 edition = "2021"
-rust-version = "1.56.1"
+rust-version = "1.63.0"
 version = "0.0.1"
 authors = ["Generated by fuzz/generate-files.sh"]
 publish = false

src/plan.rs

@@ -289,7 +289,6 @@ impl Plan {
                 stack
                     .into_iter()
                     .fold(Builder::new(), |builder, item| {
-                        use core::convert::TryFrom;
                         let bytes = PushBytesBuf::try_from(item)
                             .expect("All the possible placeholders can be made into PushBytesBuf");
                         builder.push_slice(bytes)

src/primitives/threshold.rs

@@ -55,7 +55,7 @@ impl<T, const MAX: usize> Threshold<T, MAX> {
     /// Constructs a threshold directly from a threshold value and collection.
     pub fn new(k: usize, inner: Vec<T>) -> Result<Self, ThresholdError> {
         if k == 0 || k > inner.len() || (MAX > 0 && inner.len() > MAX) {
-            Err(ThresholdError { k, n: inner.len(), max: (MAX > 0).then(|| MAX) })
+            Err(ThresholdError { k, n: inner.len(), max: (MAX > 0).then_some(MAX) })
         } else {
             Ok(Threshold { k, inner })
         }
@@ -68,7 +68,7 @@ impl<T, const MAX: usize> Threshold<T, MAX> {
         // Do an early return if our minimum size exceeds the max.
         if MAX > 0 && min_size > MAX {
             let n = iter.count();
-            return Err(ThresholdError { k, n, max: (MAX > 0).then(|| MAX) });
+            return Err(ThresholdError { k, n, max: (MAX > 0).then_some(MAX) });
         }
 
         let mut inner = Vec::with_capacity(min_size);