59.mdx

fork	group
Frontier	Stack Memory Storage and Flow Operations

Index 1 is top of the stack. See PUSH.

Notes

The memory is always fully accessible. What this instruction tracks is the highest offset that was accessed in the current execution. A first write or read to a bigger offset will trigger a memory expansion, which will cost gas. The size is always a multiple of a word (32 bytes).

Stack output

0. size: current memory size in bytes (higher offset accessed until now + 1).

Example

See in playground

Error cases

The state changes done by the current context are reverted in those cases:

• Not enough gas.
• Stack overflow.