From 0c8164776c6cfe881a4820cf4d2f53a490433c68 Mon Sep 17 00:00:00 2001
From: Christopher Schwan <handgranaten-herbert@posteo.de>
Date: Wed, 22 Feb 2023 09:55:16 +0100
Subject: [PATCH] Lower MSRV to 1.64

---
 .github/workflows/capi.yaml        | 2 +-
 .github/workflows/rust.yml         | 2 +-
 Cargo.toml                         | 2 +-
 README.md                          | 2 +-
 docs/installation.md               | 2 +-
 pineappl/src/grid.rs               | 9 +++++++--
 pineappl_cli/src/import/fastnlo.rs | 9 +++++++--
 7 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/capi.yaml b/.github/workflows/capi.yaml
index d67c81be..a87136fc 100644
--- a/.github/workflows/capi.yaml
+++ b/.github/workflows/capi.yaml
@@ -15,7 +15,7 @@ jobs:
         uses: actions-rs/toolchain@v1
         with:
           default: true
-          toolchain: 1.65.0
+          toolchain: 1.64.0
 
       - name: Install cargo-c
         run: |
diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 1a709d85..d99992cd 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -43,7 +43,7 @@ jobs:
       uses: actions-rs/toolchain@v1
       with:
         default: true
-        toolchain: 1.65.0
+        toolchain: 1.64.0
         components: llvm-tools-preview
     - name: Get test data
       id: cache-test-data
diff --git a/Cargo.toml b/Cargo.toml
index 34e896f7..c209c18a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,7 +19,7 @@ edition = "2021"
 keywords = ["high-energy-physics", "physics"]
 license = "GPL-3.0-or-later"
 repository = "https://github.com/NNPDF/pineappl"
-rust-version = "1.65.0"
+rust-version = "1.64.0"
 version = "0.5.9"
 
 [profile.release]
diff --git a/README.md b/README.md
index ab294f46..5ea3f716 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 [![codecov](https://codecov.io/gh/NNPDF/pineappl/branch/master/graph/badge.svg)](https://codecov.io/gh/NNPDF/pineappl)
 [![Documentation](https://docs.rs/pineappl/badge.svg)](https://docs.rs/pineappl)
 [![crates.io](https://img.shields.io/crates/v/pineappl.svg)](https://crates.io/crates/pineappl)
-[![MSRV](https://img.shields.io/badge/Rust-1.65+-lightgray.svg)](docs/installation.md)
+[![MSRV](https://img.shields.io/badge/Rust-1.64+-lightgray.svg)](docs/installation.md)
 
 # What is PineAPPL?
 
diff --git a/docs/installation.md b/docs/installation.md
index a9c798df..ab3ab382 100644
--- a/docs/installation.md
+++ b/docs/installation.md
@@ -139,7 +139,7 @@ already installed, make sure it is recent enough:
 
     cargo --version
 
-This should show a version that is at least 1.65.0. If you do not have `cargo`
+This should show a version that is at least 1.64.0. If you do not have `cargo`
 or if it is too old, go to <https://www.rust-lang.org/tools/install> and follow
 the instructions there.
 
diff --git a/pineappl/src/grid.rs b/pineappl/src/grid.rs
index 455e2cf0..6f986178 100644
--- a/pineappl/src/grid.rs
+++ b/pineappl/src/grid.rs
@@ -532,8 +532,13 @@ impl Grid {
                     continue;
                 }
 
-                let Some(bin_index) = bin_indices.iter().position(|&index| index == bin)
-                    else { continue };
+                // TODO: use let-else statement when MSRV is 1.65
+                let bin_index =
+                    if let Some(bin) = bin_indices.iter().position(|&index| index == bin) {
+                        bin
+                    } else {
+                        continue;
+                    };
 
                 if subgrid.is_empty() {
                     continue;
diff --git a/pineappl_cli/src/import/fastnlo.rs b/pineappl_cli/src/import/fastnlo.rs
index 9e3432b0..deb96045 100644
--- a/pineappl_cli/src/import/fastnlo.rs
+++ b/pineappl_cli/src/import/fastnlo.rs
@@ -452,8 +452,13 @@ pub fn convert_fastnlo_table(file: &fastNLOLHAPDF, alpha: u32, dis_pid: i32) ->
         // TODO: there doesn't seem to be a better way than trying an index and stopping whenever a
         // NULL pointer is returned
         let coeff_base = file_as_table.GetCoeffTable(id);
-        let Some(coeff_base) = (unsafe { coeff_base.as_ref() })
-            else { break; };
+
+        // TODO: use let-else statement when MSRV is 1.65
+        let coeff_base = if let Some(base) = unsafe { coeff_base.as_ref() } {
+            base
+        } else {
+            break;
+        };
 
         if !coeff_base.IsEnabled() {
             break;