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Severity: gas
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## [G-23] Structs can be packed into fewer storage slots by editing time variables

saq

Summary

[G-23] Structs can be packed into fewer storage slots by editing time variables

The following structures could be optimized moving the position of certain values in order to save a lot slots:

Enums are represented by integers; the possibility listed first by 0, the next by 1, and so forth.
An enum type just acts like uintN, where N is the smallest legal value large enough to accomodate all the possibilities.

Refference: https://ethdebug.github.io/solidity-data-representation

https://docs.soliditylang.org/en/v0.8.17/internals/layout_in_storage.html#storage-inplace-encoding

file: /src/interfaces/ISwapRouter.sol
​
​
5 struct ExactInputSingleParams {
address tokenIn;
address tokenOut;
uint24 fee;
address recipient;
uint256 deadline;
uint256 amountIn;
uint256 amountOutMinimum;
uint160 sqrtPriceLimitX96;
15 }
​

https://github.com/Cyfrin/2023-07-beedle/blob/main/src/interfaces/ISwapRouter.sol#L5-L15

Recommended Code

​
/// @audit the uint24 fee variabel is cut and past on the bottom.
​
struct ExactInputSingleParams {
address tokenIn;
address tokenOut;
address recipient;
uint256 deadline;
uint256 amountIn;
uint256 amountOutMinimum;
+ + uint24 fee;
uint160 sqrtPriceLimitX96;

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