Tag: traits

Rust’s generics, characteristics and life cycle (3): Traits: define common behavior

Development environment Windows 10 Rust 1.70.0 VS Code 1.79.2 Project Engineering Here continue to use the last project rust-demo Traits: define common behavior Trait defines functionality that a particular type has and can share with other types. We can use traits to define shared behavior in an abstract way. We can use trait bounds to […]

About Scala’s use of traits to implement multiple inheritance conflict resolution mechanisms and superimposed traits

First, the construction order of Scala: This refers to the construction order when a superclass and one or more traits are extended when creating a class, or when a class object is mixed with traits. (There must be no order when there is only a single class) Suppose there is a parent trait, trait1, and […]

Master Scala classes, objects, abstract classes and traits

Zero, learning objectives for this section Master class definition and instantiation Understanding Singleton Objects and Companion Objects Mastering Constructors and Auxiliary Constructors Mastering abstract classes and traits 1. Class (1) Class definition Objects are concrete instances of classes. Classes are abstract and do not occupy memory, while objects are concrete and occupy storage space. One […]

Study Rust Bible analysis – Rust learn-16 (advanced traits, macros)

Study the Rust Bible analysis – Rust learn-16 (advanced traits, macros) advanced traits Association Type Why not use generics but Type Operator overloading (low importance level) Duplicate method disambiguation never type The value of continue is ! return closure macro Custom macros (declaration macros) How macros work Rust compilation process Create new blank macro macro […]

Study Rust Bible analysis – Rust learn-10 (generics, traits, life cycle)

Study the Rust Bible analysis – Rust learn-10 (generics, traits, life cycle) generic apply generic methods generic structure enum generic Generics in method definitions trait define a trait Default trait method implementation Implement traits for structs Call the method implemented in the trait takes the trait as a parameter trait bound Multiple implementations of input […]

Scala generics (generic methods, generic classes, generic traits, upper and lower bounds, covariant, contravariant, invariant)

Article directory 1. Generics 1.1 Generic methods 1.2 Generic classes 1.3 Generic traits 2. Upper and lower bounds 2.1 Upper bound 2.2 Lower bound 3. Covariant, contravariant, invariant 3.1 Invariant 3.2 Covariance 3.3 Inversion 3.4 Examples 1. Generic Generic means that generally refers to a specific data type. In Scala, generics are represented by [data […]

[Solved] SLAM installation eigen error: error: no type named Literal’ in struct Eigen::NumTraits<ceres::Jet<double, 9>>’

Eigen3 compilation and installation error when installing ceres-solver Error: error: no type named Literal’ in struct Eigen::NumTraits’ Eigen3 compile and install error when installing pcl Error in /usr/local/include/eigen3/Eigen/src/Core/products/Parallelizer.h:162:40: error: ‘eigen_assert_exception’ is not a member of ‘Eigen’ if (errorCount) EIGEN_THROW_X(Eigen::eigen_assert_exception ()); The reason for this is because eigen3 is incompatible with the ceres-solver version and the […]

[Solved] resolve undefined reference to cv::imread(std::__cxx11::basic_string<char, std::char_traits<char>,….

When using opencv, you may encounter undefined reference to cv::imread(std::__cxx11::basic_string const & amp;, int)’ The main reason is that the version of the function used and the version of the referenced library function are different, and it is necessary to ensure that the version of the used function and the referenced library function is the […]