Use explicit imports (#4399)

Co-authored-by: Hadrien Croubois <hadrien.croubois@gmail.com>
Co-authored-by: ernestognw <ernestognw@gmail.com>

Author: 3 people

.changeset/orange-apes-draw.md

@@ -0,0 +1,5 @@
+---
+'openzeppelin-solidity': major
+---
+
+Switched to using explicit Solidity import statements. Some previously available symbols may now have to be separately imported.

.solhint.json

@@ -9,6 +9,7 @@
     "modifier-name-mixedcase": "error",
     "private-vars-leading-underscore": "error",
     "var-name-mixedcase": "error",
-    "imports-on-top": "error"
+    "imports-on-top": "error",
+    "no-global-import": "error"
   }
 }

README.md

@@ -48,7 +48,7 @@ Once installed, you can use the contracts in the library by importing them:
 ```solidity
 pragma solidity ^0.8.19;
 
-import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
+import {ERC721} from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
 
 contract MyCollectible is ERC721 {
     constructor() ERC721("MyCollectible", "MCO") {

contracts/access/AccessControl.sol

@@ -3,10 +3,10 @@
 
 pragma solidity ^0.8.19;
 
-import "./IAccessControl.sol";
-import "../utils/Context.sol";
-import "../utils/Strings.sol";
-import "../utils/introspection/ERC165.sol";
+import {IAccessControl} from "./IAccessControl.sol";
+import {Context} from "../utils/Context.sol";
+import {Strings} from "../utils/Strings.sol";
+import {ERC165} from "../utils/introspection/ERC165.sol";
 
 /**
  * @dev Contract module that allows children to implement role-based access

contracts/access/AccessControlDefaultAdminRules.sol

@@ -3,10 +3,11 @@
 
 pragma solidity ^0.8.19;
 
-import "./AccessControl.sol";
-import "./IAccessControlDefaultAdminRules.sol";
-import "../utils/math/SafeCast.sol";
-import "../interfaces/IERC5313.sol";
+import {AccessControl, IAccessControl} from "./AccessControl.sol";
+import {IAccessControlDefaultAdminRules} from "./IAccessControlDefaultAdminRules.sol";
+import {SafeCast} from "../utils/math/SafeCast.sol";
+import {Math} from "../utils/math/Math.sol";
+import {IERC5313} from "../interfaces/IERC5313.sol";
 
 /**
  * @dev Extension of {AccessControl} that allows specifying special rules to manage

contracts/access/AccessControlEnumerable.sol

@@ -3,9 +3,9 @@
 
 pragma solidity ^0.8.19;
 
-import "./IAccessControlEnumerable.sol";
-import "./AccessControl.sol";
-import "../utils/structs/EnumerableSet.sol";
+import {IAccessControlEnumerable} from "./IAccessControlEnumerable.sol";
+import {AccessControl} from "./AccessControl.sol";
+import {EnumerableSet} from "../utils/structs/EnumerableSet.sol";
 
 /**
  * @dev Extension of {AccessControl} that allows enumerating the members of each role.

contracts/access/IAccessControlDefaultAdminRules.sol

@@ -3,7 +3,7 @@
 
 pragma solidity ^0.8.19;
 
-import "./IAccessControl.sol";
+import {IAccessControl} from "./IAccessControl.sol";
 
 /**
  * @dev External interface of AccessControlDefaultAdminRules declared to support ERC165 detection.

contracts/access/IAccessControlEnumerable.sol

@@ -3,7 +3,7 @@
 
 pragma solidity ^0.8.19;
 
-import "./IAccessControl.sol";
+import {IAccessControl} from "./IAccessControl.sol";
 
 /**
  * @dev External interface of AccessControlEnumerable declared to support ERC165 detection.

contracts/access/Ownable.sol

@@ -3,7 +3,7 @@
 
 pragma solidity ^0.8.19;
 
-import "../utils/Context.sol";
+import {Context} from "../utils/Context.sol";
 
 /**
  * @dev Contract module which provides a basic access control mechanism, where

contracts/access/Ownable2Step.sol

@@ -3,7 +3,7 @@
 
 pragma solidity ^0.8.19;
 
-import "./Ownable.sol";
+import {Ownable} from "./Ownable.sol";
 
 /**
  * @dev Contract module which provides access control mechanism, where