default-value

问题 The following code compiles and works as expected. #include <vector> void function(std::vector<int> vec, int size=1); int main(){ std::vector<int> vec = {1,2,3}; function(vec); } void function(std::vector<int> vec, int size){ //code.. return; } However, I would like the size parameter's default value to be deduced based on a previous parameter. So for example: void function(std::vector<int> vec, int size=vec.size()); But this however results in: error: local variable ‘vec’ may not appear in

问题 In my code i have int s, bool s, pointer s and so on, i also have some type defined by me with typedef , how can i manage the default value initialization like it happens in the objects with the contrunctor? I want to be sure that T var; if untouched, is always equal to my default value and i like to do this without parsing each line of code anche changing the default value manually and without using a preprocessor macro. is this possible? for a new typedef is possible to define a default

问题 Which is the default value for the output color in GLSL in case you dont set it? #version 330 uniform sampler2DRect colorTex; uniform vec3 backgroundColor; out vec4 outputColor; void main(void) { vec4 frontColor = texture(colorTex, gl_FragCoord.xy); outputColor.rgb = frontColor + backgroundColor * frontColor.a; } Is it (0, 0, 0, 1)? Ps: that code belongs to the old GL, trying to use it with the GL3, I get the following error error C7011: implicit cast from "vec4" to "vec3" I am right to

问题 This stems from a previous question I asked - about a write conflict with a form, but the problem seems to be originating from the fact that I can update existing records in a linked table provided by one System DSN, but not another linked table provided by another DSN (different database) - allowing me to enter records at first, but then preventing me from making any changes to the records as if another user has changed the data before me. There are no check constraints defined on the server

问题 I have a dropdown button which works fine, but when I try to set a default value it will fail with the following error: 'package:flutter/src/material/dropdown.dart': Failed assertion: line 620 pos 15: 'items == null || items.isEmpty || value == null || items.where((DropdownMenuItem item) => item.value == value).length == 1': is not true. This is my dropdown button: Widget changeWorkspace() { return StatefulBuilder( builder: (BuildContext context, StateSetter setState) { return Column

问题 I'm trying to build a script to generate ALTER TABLE queries so that across whole schemas, columns are adjusted to be compatible with MySQL strict-mode.. I want it to be a simple as possible, making the most basic changes possible for NOT/NOT NULL and Default values to ensure strict-mode compatibility, but at the same time minimising the chances of breaking any existing queries, or associated PHP code that depends on the schema definition's workings. Any tips / things I've missed out / things

问题 Is there a way to set a default value for a picker? I save the last selected row from all the pickers and I want to be able to have the pickers load those saved rows at start up. As of now I have found this code: [settingsPagePicker selectRow:3 inComponent:0 animated:YES]; It works but only when the user taps the picker. I need it to work when the app is first loaded. If I put this code at viewDidLoad the app will crash. Anyone know where the proper place to put this in my code to make it

问题 Is there a way to change the default <mainIndex><maxFieldLength> value in the solarconfig.xml file, so that when a Solr collection is created ALL collections will use the new value? The default value of 10000 is okay for most applications, but most of the PDFs I am working with are over 100 pages. The client is concerned that the search results do not return EVERY PDF containing the given keywords. Correct me if I'm wrong, but I'm pretty sure that the maxFieldLength is limiting the indexing

问题 I am having a problem returning a default DateTime value from a complex Linq-to-Sql query. Hopefully the following simplified example shows the problem (although I haven't run this exact code): users.Select(u => new MyDomainObject( u.Id, u.Transactions .Where(t => false) // empty results set .Select(t => t.TransactionTime) // TransactionTime is DATETIME NOT NULL .OrderByDescending(x => x) .FirstOrDefault() // I want DateTime.MinValue (or SqlDateTime.MinValue) ) ); So I want the last timestamp

问题 Adding following Record Fields to the GridPanel Store makes the site throw a JavaScript Error Uncaught SyntaxError: Unexpected identifier to the Chrome Console <ext:RecordField Name="listname" AllowBlank="false" DefaultValue="Listname" /> <ext:RecordField Name="recipients" AllowBlank="false" DefaultValue="Listmembers" /> <ext:RecordField Name="usage" AllowBlank="true" /> <ext:RecordField Name="responsible" AllowBlank="false" DefaultValue="please add Responsible Person(s)/ Group(s)" /> Firebug