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`is_[condition]`: Boolean Check

src/idiomatic/foundations-api-design/predictable-api/naming-conventions/is.md

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<!-- Copyright 2025 Google LLC SPDX-License-Identifier: CC-BY-4.0 -->

is_[condition]: Boolean Check

Check a condition about a datatype.

rust,compile_fail
# // Copyright 2025 Google LLC
# // SPDX-License-Identifier: Apache-2.0
#
impl <T> Vec<T> {
    is_empty(&self) -> bool;
}

impl f32 {
    is_nan(self) -> bool;
}

impl u32 {
    is_power_of_two(self) -> bool;
}
<details> - A boolean condition on a value.

  • is prefix is preferred over methods with not in the name.

    There are no instances of is_not_ in standard library methods, just use !value.is_[condition].

</details>