struct

问题 I'd like to validate the following structure : type CarModel struct { gorm.Model OwnerID int `json:"ownerid" validate:"nonzero"` Type string `json:"type" validate:"regexp=(?)(A|B)"` A string `json:"url" validate:"isurl"` B string `json:"ip" validate:"isip"` } I would like to validate A and B depending on Type, if type = A then A must exist and must be a URL BUT B must not exist if type = B then A must not exist and B must be an IP is this possible with validator ? I did try custom validation

问题 I am sure that this question has been asked and answered before, but I am having trouble searching without the proper terminology. I have two unique structs A & B (not classes). My code uses functional overloading to treat the structs differently. I don't understand how to handle the declaration polymorphism. I apologize for a pseudocode example. if( flag ==1 ){ declare stuct A scoped to main } else{ declare stuct B scoped to main } The pseudo code above will not work since the declarations

问题 Disclaimer: I took the following example from the Python Cookbook (O'Reilly). Let's say I have the following simple struct : typedef struct { double x,y; } Point; with a function that calculates the Euclidean distance between two Point s: extern double distance(Point* p1, Point* p2); All this is part of a shared library called points : points.h - the header file points.c - the source file libpoints.so - the library file (the Cython extension links against it) I have created my wrapping Python

问题 I have the following code: struct Product { var image: URL! var title: String! var price: Price! var rating: Float! var url: URL! } struct Price { var value: Double! var currency: String! // should be enum } I later initialize a Product with: product = Product( image: URL(string: "...")!, title: "...", price: Price( value: 5.99, currency: "CAD" ), rating: 4.5, url: URL(string: "...")! ) During runtime, product.price is of type Price? I find this weird since it's implicitly unwrapped. I've

问题 In my project I need to do something like: use std::thread; use std::time::Duration; struct A { pub ints: Vec<u8>, } impl A { fn new() -> A { let mut a = A { ints: vec![1, 5, 6, 2, 3, 4], }; a.timer(); a } fn timer(&mut self) { thread::spawn(move || { loop { thread::sleep(Duration::from_millis(1)); self.ints.remove(0); } }); } } fn main() { let a = A::new(); loop { println!("Remaining elements: {:?}", a.ints); } } The idea is that some struct contains a vector of elements. These elements

问题 In my project I need to do something like: use std::thread; use std::time::Duration; struct A { pub ints: Vec<u8>, } impl A { fn new() -> A { let mut a = A { ints: vec![1, 5, 6, 2, 3, 4], }; a.timer(); a } fn timer(&mut self) { thread::spawn(move || { loop { thread::sleep(Duration::from_millis(1)); self.ints.remove(0); } }); } } fn main() { let a = A::new(); loop { println!("Remaining elements: {:?}", a.ints); } } The idea is that some struct contains a vector of elements. These elements

问题 I'm trying to create a function that creates a variable sized 2D funct array. I'm using the following code, which seems to work just fine on its own: typedef struct { //Starter Properties int TypeB; int TypeF; int TypeW; //Randomized Properties int RandB; int RandF; int RandW; //Derived Properties int Speed; } MapTileData; MapTileData **Map; int i, x=5, y=5; //Allocate Initial Space Map = (MapTileData**)calloc(x, sizeof(MapTileData)); for(i = 0; i < x; i++) { Map[i] = (MapTileData*)calloc(y,

问题 Say I have a struct like this: struct vertexNodeInfo { unsigned char level; int node; double leaf; }; If I then had this: vector<vertexNodeInfo> node; How big (memory-wise, not .size ) would the empty vector be, before any push_back ? Would it be exactly the same size (again, in terms of memory) as vector<int> node; ? 回答1: There's no requirement. Even more, it's a poorly formulated question. The .size of the vector would be 0 , because it has no elements. The sizeof isn't affected the number

问题 Say I have a struct like this: struct vertexNodeInfo { unsigned char level; int node; double leaf; }; If I then had this: vector<vertexNodeInfo> node; How big (memory-wise, not .size ) would the empty vector be, before any push_back ? Would it be exactly the same size (again, in terms of memory) as vector<int> node; ? 回答1: There's no requirement. Even more, it's a poorly formulated question. The .size of the vector would be 0 , because it has no elements. The sizeof isn't affected the number

问题 I have two functions here, which for intarr_set(), if an index is valid, I would set the value at ia[index] to val and return INTARR_OK which is a status code, and the other function intarr_get() would set *i to ia[index] if the index is valid as well. But when I was testing my function with a random array I generated, which was [ 11 49 36 3 69 21 72 73 94 69 2 22 2 96 64 93 ], I got a message saying that my intarr_get() function didn't return INTARR_OK even though I got a valid index. Does