Set util MSRV to 1.82, add util MSRV policy (#7125)

fixes #7114

Based on WG conclusion in
#7066 (comment)

Author: Manishearth

documents/process/rust_versions.md

@@ -18,11 +18,9 @@ The main ICU4X library does not use nightly; however nightly is required for bui
 
 Our "utils" crates (yoke, zerovec, zerofrom, etc) are not versioned alongside ICU4X: they may have major version updates between minor ICU4X releases, and they may choose to have minor version updates between major ICU4X releases.
 
-By default, these crates have the same MSRV as their corresponding ICU4X release, however at times we may give them a lower MSRV for a wider range of compatability.
+We intend for these crates to gain wider adoption than just ICU4X. As such, these crates don't change their MSRV unless there is a need for it.
 
-This is done on an as-requested basis and is best-effort.
-
-Currently, `zerofrom` is the only crate with a lower MSRV.
+When an ICU4X developer needs to use a new Rust API/feature in such a crate, they may update the MSRV to any Rust version at least six Rust versions before the current stable Rust (and also less than or equal to the current ICU4X MSRV).
 
 ## For ICU4X developers
 

utils/bies/Cargo.toml

@@ -13,7 +13,7 @@ homepage.workspace = true
 include.workspace = true
 license.workspace = true
 repository.workspace = true
-rust-version.workspace = true
+rust-version = "1.82"
 
 [package.metadata.workspaces]
 independent = true

utils/calendrical_calculations/Cargo.toml

@@ -18,7 +18,7 @@ authors.workspace = true
 edition.workspace = true
 include.workspace = true
 repository.workspace = true
-rust-version.workspace = true
+rust-version = "1.82"
 
 
 # This is a special exception: The algorithms in this crate are based on "Calendrical Calculations" by Reingold and Dershowitz

utils/crlify/Cargo.toml

@@ -14,7 +14,7 @@ edition.workspace = true
 include.workspace = true
 license.workspace = true
 repository.workspace = true
-rust-version.workspace = true
+rust-version = "1.82"
 
 [package.metadata.workspaces]
 independent = true

utils/databake/Cargo.toml

@@ -14,7 +14,7 @@ edition.workspace = true
 include.workspace = true
 license.workspace = true
 repository.workspace = true
-rust-version.workspace = true
+rust-version = "1.82"
 
 [package.metadata.workspaces]
 independent = true

utils/databake/derive/Cargo.toml

@@ -14,7 +14,7 @@ edition.workspace = true
 include.workspace = true
 license.workspace = true
 repository.workspace = true
-rust-version.workspace = true
+rust-version = "1.82"
 
 [package.metadata.workspaces]
 independent = true

utils/env_preferences/Cargo.toml

@@ -7,7 +7,7 @@ name = "env_preferences"
 version = "0.1.0"
 publish = false
 
-rust-version.workspace = true
+rust-version = "1.82"
 authors.workspace = true
 edition.workspace = true
 repository.workspace = true

utils/fixed_decimal/Cargo.toml

@@ -13,7 +13,7 @@ edition.workspace = true
 include.workspace = true
 license.workspace = true
 repository.workspace = true
-rust-version.workspace = true
+rust-version = "1.82"
 
 [package.metadata.workspaces]
 independent = true

utils/ixdtf/Cargo.toml

@@ -14,7 +14,7 @@ homepage.workspace = true
 include.workspace = true
 license.workspace = true
 repository.workspace = true
-rust-version.workspace = true
+rust-version = "1.82"
 
 [package.metadata.workspaces]
 independent = true

utils/litemap/Cargo.toml

@@ -14,7 +14,7 @@ edition.workspace = true
 include.workspace = true
 license.workspace = true
 repository.workspace = true
-rust-version.workspace = true
+rust-version = "1.82"
 
 [package.metadata.workspaces]
 independent = true