Implicit Pure

Property	Value
Rule Code	NTX5
Severity	Style

Background

Similar to the implicit view rule. Using the @pure decorator for functions that don't access state is not enforced by the compiler, but helps querying the function off-chain and helps preventing the introduction of side effects in the function.

Purpose

Detects when functions that don't access state at all are missing the @pure decorator.

Example

# Non-compliant - function doesn't access state but isn't marked as @pure
@external
def calculate_sum(_a: uint256, _b: uint256) -> uint256:
    return _a + _b

# Compliant
@pure
@external
def calculate_sum_pure(_a: uint256, _b: uint256) -> uint256:
    return _a + _b

The first calculate_sum function would be flagged by this rule because it doesn't access state at all but is not marked as @pure.