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length

boost_geometry::algorithm

Function length 

Source 
pub fn length<G>(
    g: &G,
) -> <<<<<G as Geometry>::Point as Point>::Cs as CoordinateSystem>::Family as DefaultLength<<<<G as Geometry>::Point as Point>::Cs as CoordinateSystem>::Family>>::Strategy as LengthStrategy<G>>::Out
where
    G: Linestring,
    <<<G as Geometry>::Point as Point>::Cs as CoordinateSystem>::Family: DefaultLength<<<<G as Geometry>::Point as Point>::Cs as CoordinateSystem>::Family>,
    <<<<G as Geometry>::Point as Point>::Cs as CoordinateSystem>::Family as DefaultLength<<<<G as Geometry>::Point as Point>::Cs as CoordinateSystem>::Family>>::Strategy: LengthStrategy<G> + Default,
Expand description

Sum the per-segment distance along a linestring using the default strategy for its coordinate-system family.

Mirrors boost::geometry::length from boost/geometry/algorithms/length.hpp. The strategy is resolved via geometry_strategy::DefaultLengthStrategy — Cartesian input resolves to the Pythagorean geometry_strategy::CartesianLength (identical to the v1 behaviour), spherical to Haversine, geographic to Andoyer. For an explicit strategy use length_with.

§Behaviour on “wrong” kinds

This static entry point deliberately compile-errors on a Point or Polygon argument (Boost returns 0 at runtime; when the kind is known at compile time a type error is a clearer signal). The runtime contract — Boost’s “length of a non-linear kind is 0” (length.hpp:75-80) — is honoured on the dynamic path instead: crate::length_dyn returns 0 for Point, Polygon, MultiPoint, ….