# QueryConstructionError

- **Package:** libtmux-swift
- **Language:** Swift
- **Kind:** enum
- **Source:** https://github.com/libtmux/libtmux-swift/blob/254f8b2be7eb60cacc3ffcb3ea8e456784f582df/Sources/LibTmux/FilterExpr.swift#L42
- **Page:** https://libtmux.org/en/swift/latest/reference/queryconstructionerror/

Why a filter could not be built.

## Members

- `!=(_:_:)` (function): Returns a Boolean value indicating whether two values are not equal.
- `localizedDescription` (property): Retrieve the localized description for this error.
- `unknownField` (constant): The key path does not name a filterable field of this model.
- `invalidOperation(_:)` (constant): The field and operator could not form a safe expression.