# VersionedInitializable

[Git Source](https://github.com/isle-labs/isle-contract/blob/main/contracts/libraries/upgradability/VersionedInitializable.sol)

**Author:** Aave, inspired by the OpenZeppelin Initializable contract

Helper contract to implement initializer functions. To use it, replace the constructor with a function that has the `initializer` modifier.

*WARNING: Unlike constructors, initializer functions must be manually invoked. This applies both to deploying an Initializable contract, as well as extending an Initializable contract via inheritance. WARNING: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or ensure that all initializers are idempotent, because this is not dealt with automatically as with constructors.*

## State Variables

### INITIALIZABLE\_STORAGE

```solidity
bytes32 private constant INITIALIZABLE_STORAGE = 0xf0c57e16840df040f15088dc2f81fe391c3923bec73e23a9662efc9c229c6a00;
```

### **\_\_**gap

```solidity
uint256[50] private ______gap;
```

## Functions

### initializer

*Modifier to use in the initializer function of a contract.*

```solidity
modifier initializer();
```

### onlyInitializing

*Modifier to use when a function is restricted to the initialization phase.*

```solidity
modifier onlyInitializing();
```

### getRevision

Returns the revision number of the contract

*Needs to be defined in the inherited class as a constant.*

```solidity
function getRevision() public pure virtual returns (uint256);
```

**Returns**

| Name     | Type      | Description         |
| -------- | --------- | ------------------- |
| `<none>` | `uint256` | The revision number |

### isConstructor

Returns true if and only if the function is running in the constructor

```solidity
function isConstructor() private view returns (bool);
```

**Returns**

| Name     | Type   | Description                                        |
| -------- | ------ | -------------------------------------------------- |
| `<none>` | `bool` | True if the function is running in the constructor |

### \_getInitializableStorage

```solidity
function _getInitializableStorage() private pure returns (VersionedInitializableStorage storage $);
```

### \_getLastInitializedRevision

```solidity
function _getLastInitializedRevision() internal view returns (uint256);
```

### \_getInitializing

```solidity
function _getInitializing() internal view returns (bool);
```

## Structs

### VersionedInitializableStorage

*Indicates that the contract has been initialized.*

```solidity
struct VersionedInitializableStorage {
    uint256 lastInitializedRevision;
    bool initializing;
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.isle.finance/contract-documentation/libraries/upgradability/versionedinitializable.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.