CRS（坐标参考系统）定义。

来源于 https://github.com/DanielJDufour/crs-csv.

示例

通过常量直接访问CRS定义

let def = crs_definitions::EPSG_4326;

assert_eq!(
    def.proj4,
    r#"+proj=longlat +datum=WGS84 +no_defs"#,
);

assert_eq!(
    def.wkt,
    r#"GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]"#,
);

通过EPSG代码查找CRS定义

let def = crs_definitions::from_code(4326);

assert_eq!(def, Some(crs_definitions::EPSG_4326));

通过常量EPSG代码查找CRS定义

const def: Def = crs_definitions::from_code_const::<4326>();

assert_eq!(def, crs_definitions::EPSG_4326);