In Solidity, how does the slot assignation work for storage variables when there's inheritance?
In a simple solidity contract, without inheritance, storage variables get assigned sequentially starting from slot 0.
But in case of inheritance, the inherited variables appear before or afterwards?
inheritance storage solidity
asked Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
migrated from stackoverflow.com Dec 2 '18 at 2:07
This question came from our site for professional and enthusiast programmers.
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In a simple solidity contract, without inheritance, storage variables get assigned sequentially starting from slot 0.
But in case of inheritance, the inherited variables appear before or afterwards?
inheritance storage solidity
asked Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
migrated from stackoverflow.com Dec 2 '18 at 2:07
This question came from our site for professional and enthusiast programmers.
add a comment |
In a simple solidity contract, without inheritance, storage variables get assigned sequentially starting from slot 0.
But in case of inheritance, the inherited variables appear before or afterwards?
inheritance storage solidity
asked Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
In a simple solidity contract, without inheritance, storage variables get assigned sequentially starting from slot 0.
But in case of inheritance, the inherited variables appear before or afterwards?
inheritance storage solidity
inheritance storage solidity
asked Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
asked Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
asked Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
asked Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
asked Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
264
migrated from stackoverflow.com Dec 2 '18 at 2:07
This question came from our site for professional and enthusiast programmers.
migrated from stackoverflow.com Dec 2 '18 at 2:07
This question came from our site for professional and enthusiast programmers.
add a comment |
add a comment |
1 Answer
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The assignment is as follows: first to the inherited variables, from the leftmost contract to the rightmost, finishing with the current contract you're in.
In the following example C inherits from Base and Base2, in that order. The slot assignment will start from Base, following Base2, and finally C.
pragma solidity ^0.5;
contract Base {
uint256 basevar = 0;
constructor() public {
basevar = 1;
}
}
contract Base2 {
uint256 basevar2 = 2;
constructor() public {
basevar2 = 1;
}
}
contract C is Base, Base2 {
uint256 cvar = 0;
function getCvar() public view returns(uint256) {
return cvar;
}
function getBasevar () public view returns(uint256) {
return basevar;
}
}
basevar gets assigned slot 0,
basevar2 gets assigned slot 1,
and cvar gets assigned slot 2.
answered Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
add a comment |
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1 Answer
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1 Answer
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The assignment is as follows: first to the inherited variables, from the leftmost contract to the rightmost, finishing with the current contract you're in.
In the following example C inherits from Base and Base2, in that order. The slot assignment will start from Base, following Base2, and finally C.
pragma solidity ^0.5;
contract Base {
uint256 basevar = 0;
constructor() public {
basevar = 1;
}
}
contract Base2 {
uint256 basevar2 = 2;
constructor() public {
basevar2 = 1;
}
}
contract C is Base, Base2 {
uint256 cvar = 0;
function getCvar() public view returns(uint256) {
return cvar;
}
function getBasevar () public view returns(uint256) {
return basevar;
}
}
basevar gets assigned slot 0,
basevar2 gets assigned slot 1,
and cvar gets assigned slot 2.
answered Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
add a comment |
The assignment is as follows: first to the inherited variables, from the leftmost contract to the rightmost, finishing with the current contract you're in.
In the following example C inherits from Base and Base2, in that order. The slot assignment will start from Base, following Base2, and finally C.
pragma solidity ^0.5;
contract Base {
uint256 basevar = 0;
constructor() public {
basevar = 1;
}
}
contract Base2 {
uint256 basevar2 = 2;
constructor() public {
basevar2 = 1;
}
}
contract C is Base, Base2 {
uint256 cvar = 0;
function getCvar() public view returns(uint256) {
return cvar;
}
function getBasevar () public view returns(uint256) {
return basevar;
}
}
basevar gets assigned slot 0,
basevar2 gets assigned slot 1,
and cvar gets assigned slot 2.
answered Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
add a comment |
The assignment is as follows: first to the inherited variables, from the leftmost contract to the rightmost, finishing with the current contract you're in.
In the following example C inherits from Base and Base2, in that order. The slot assignment will start from Base, following Base2, and finally C.
pragma solidity ^0.5;
contract Base {
uint256 basevar = 0;
constructor() public {
basevar = 1;
}
}
contract Base2 {
uint256 basevar2 = 2;
constructor() public {
basevar2 = 1;
}
}
contract C is Base, Base2 {
uint256 cvar = 0;
function getCvar() public view returns(uint256) {
return cvar;
}
function getBasevar () public view returns(uint256) {
return basevar;
}
}
basevar gets assigned slot 0,
basevar2 gets assigned slot 1,
and cvar gets assigned slot 2.
answered Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
The assignment is as follows: first to the inherited variables, from the leftmost contract to the rightmost, finishing with the current contract you're in.
In the following example C inherits from Base and Base2, in that order. The slot assignment will start from Base, following Base2, and finally C.
pragma solidity ^0.5;
contract Base {
uint256 basevar = 0;
constructor() public {
basevar = 1;
}
}
contract Base2 {
uint256 basevar2 = 2;
constructor() public {
basevar2 = 1;
}
}
contract C is Base, Base2 {
uint256 cvar = 0;
function getCvar() public view returns(uint256) {
return cvar;
}
function getBasevar () public view returns(uint256) {
return basevar;
}
}
basevar gets assigned slot 0,
basevar2 gets assigned slot 1,
and cvar gets assigned slot 2.
answered Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
answered Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
answered Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
answered Nov 22 '18 at 22:05
Matías Aereal AeónMatías Aereal Aeón
264
264
add a comment |
add a comment |
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