lambda

问题 I have the following C# models: public class RawData { public int questionnaireId { get; set; } public int coachNodeId { get; set; } public int questionnaireNumber { get; set; } public float score { get; set; } } public class AveragedData { public int coachNodeId { get; set; } public int questionnaireNumber { get; set; } public float averageScore { get; set; } } I have an API endpoint which is returning data from a database, mapped as List<RawData> . The values are like this: questionnaireId

问题 I have the following C# models: public class RawData { public int questionnaireId { get; set; } public int coachNodeId { get; set; } public int questionnaireNumber { get; set; } public float score { get; set; } } public class AveragedData { public int coachNodeId { get; set; } public int questionnaireNumber { get; set; } public float averageScore { get; set; } } I have an API endpoint which is returning data from a database, mapped as List<RawData> . The values are like this: questionnaireId

问题 Deploying a sizeable serverless application, we had first hit the cap of 200 resources. we using serverless-plugin-split-stacks library solved that issue but possibly introduced another one later on: An error occurred: IamRoleLambdaExecution - Maximum policy size of 10240 bytes exceeded for role pca-console-production-ap-northeast-2-lambdaRole (Service: AmazonIdentityManagement; Status Code: 409; Error Code: LimitExceeded; This errors related a code lines? Any advice or suggestion would be

问题 Deploying a sizeable serverless application, we had first hit the cap of 200 resources. we using serverless-plugin-split-stacks library solved that issue but possibly introduced another one later on: An error occurred: IamRoleLambdaExecution - Maximum policy size of 10240 bytes exceeded for role pca-console-production-ap-northeast-2-lambdaRole (Service: AmazonIdentityManagement; Status Code: 409; Error Code: LimitExceeded; This errors related a code lines? Any advice or suggestion would be

问题 I have something this: template<typename T> class Image { Image(int w, int h, T defaultVal){ for(int i=0; i<h; i++) for(int j=0; j<w; j++) pixel(j, i) = defaultVal; } template<typename F> Image(int w, int h, F initializer){ for(int i=0; i<h; i++) for(int j=0; j<w; j++) pixel(j, i) = initializer(j, i); } // ... }; My intention is to be able to instantiate an Image like this: Image<int> img0(w, h, 0); // image of zeroes Image<int> imgF(w, h, [](int j, int i){ // checkerboard image return (j/10

问题 So this is how the code looks: auto generateHash = [](std::vector<File> &files) -> std::shared_ptr<std::string> { // Other code here } What does this mean? Is it a for each loop? What do the brackets in the beginning do? What do the parentheses do? What does the arrow mean? I can't compile it because of no C++11 compiler, and I can't find it in the C++ reference. 回答1: What does this mean? It's a lambda - a function object. You can call it like a function with a a vector of files (passed by

问题 I have a DateRange class that I'd like to apply to an IQueryable as a where predicate, automatically using the begin and end dates and automatically using an open or closed interval. public class DateRange { public DateTime? BeginDate { get; set; } public DateTime? EndDate { get; set; } public bool BeginInclusive { get; set; } public bool EndInclusive { get; set; } public DateRange() { BeginInclusive = true; EndInclusive = false; } public IQueryable<T> Apply<T>( IQueryable<T> source,

问题 Starting from C# 7.0 the throw keyword can be used both as an expression and as a statement, which is nice. Though, consider these overloads public static void M(Action doIt) { /*use doIt*/ } public static void M(Func<int> doIt) { /*use doIt*/ } When invoking like this M(() => throw new Exception()); or even like this (with a statement lambda) M(() => { throw new Exception(); }); the M(Func<>) overload is selected by the compiler indicating that the throw is here considered as an expression.

问题 Starting from C# 7.0 the throw keyword can be used both as an expression and as a statement, which is nice. Though, consider these overloads public static void M(Action doIt) { /*use doIt*/ } public static void M(Func<int> doIt) { /*use doIt*/ } When invoking like this M(() => throw new Exception()); or even like this (with a statement lambda) M(() => { throw new Exception(); }); the M(Func<>) overload is selected by the compiler indicating that the throw is here considered as an expression.

问题 Starting from C# 7.0 the throw keyword can be used both as an expression and as a statement, which is nice. Though, consider these overloads public static void M(Action doIt) { /*use doIt*/ } public static void M(Func<int> doIt) { /*use doIt*/ } When invoking like this M(() => throw new Exception()); or even like this (with a statement lambda) M(() => { throw new Exception(); }); the M(Func<>) overload is selected by the compiler indicating that the throw is here considered as an expression.