literals

问题 This question already has answers here : Is it possible to use std::string in a constexpr? (4 answers) Closed 4 years ago . Can C-Strings or std::string s be created as constexpr or must they be created at run-time? With gcc 4.9.2 I can do this: constexpr const char foo[] = "blee"; (Sadly the November 2013 Customer Technology Preview does not allow Visual Studio to support this: https://stackoverflow.com/a/29255013/2642059) But even with gcc 4.9.2 I cannot do this: constexpr const std::string

问题 I am trying to create a long string literal, which I store inside a std::string. If I create a literal up to approximately 2600 characters, everything prints fine. If I go beyond that number of symbols, I only get some random garbage characters printed. I have been using the C standard as guidance, environmental limits are specified as "4095 characters in a string literal (after concatenation)". But the code is written in C++. So my question is, what is the minimum amount of characters in a C

问题 I have an asp:Literal on my page ( which cannot be converted to a Label or any other control ) that I need to change the text of via JavaScript. I have the following code that works for a Label . Can anybody help? <script type="text/javascript"> function changeText() { document.getElementById('<%= Test.ClientID %>').innerHTML = 'New Text'; } </script> <a href="#" onclick='changeText()'>Change Text</a> <asp:Label id="Test" runat="server" Text="Original Text" /> Thanks UPDATE: I cannot change

问题 Can you explain how the JavaScript expression: [1 [{}]] parses/evaluates? In Firefox, Chrome, Konqueror, and rhino, it seems to create an array with a single element, undefined . However, I don't understand why. In Firefox: [1 [{}]].toSource() produces [(void 0)] Replacing 1 with other JavaScript values seems to yield the same result. Update: I think I understand now. codeka, Adrian, and CMS clarified things. As far as the standard, I tried to walk through ECMAScript 5. 1 [{}] is a Property

问题 String a = "abc"; String b = a.substring(1); b.intern(); String c = "bc"; System.out.println(b == c); The question might be foolish as intern has no major usage here, still I am confused about the fact, why does b == c results true . When String b = a.substring(1) is executed, String b references to object having "bc" Does b.intern create the literal "bc" in String Constant pool, even if it does, how come b==c result in true ? 回答1: String b = a.substring(1); returns string instance which

问题 C++14 seems to be coming and compilers are already trying to implement the core features of this new revision. I was having a look at GCC support for these core features and noticed something about the binary literals part: GCC implements them but seems to make a difference between GNU binary literals and C++14 binary literals. Here are the respective references for both: GNU binary literals C++1y binary literals I tried to find some differences between the two of them since GCC seems to make

问题 We are processing IBMEnterprise Japanese COBOL source code. The rules that describe exactly what is allowed in G type literals, and what are allowed for identifiers are unclear. The IBM manual indicates that a G'....' literal must have a SHIFT-OUT as the first character inside the quotes, and a SHIFT-IN as the last character before the closing quote. Our COBOL lexer "knows" this, but objects to G literals found in real code. Conclusion: the IBM manual is wrong, or we are misreading it. The

问题 Suppose i have the following enumerated literal enum { valueA = 5, valueB = 7, valueC = 9, valueD = 14, valueE = 15 }myEnumType; and i want to loop through each literal eg for (enumType myValEnum = valueA; myValEnum <= valueE; myValEnum++) { MyFunction(mValEnum); } will that work or will I end up calling MyFunction with values 5,6,7,8,9,10,11,12,13,14,15 ? 回答1: You can't do that, there's no support for a "foreach" type of iteration over the enumeration in C. Basically, enumerations are just

问题 Trying to query a 'Favorites' model to get a list of items a user has favorited, and then querying against a different model to get the objects back from that query to present to the template, but I'm getting an error: "invalid literal for int() with base 10" Looking over all of the other instances of that error, I couldn't find any in which the asker actually wanted to work with a comma separated list of integers, so I'm kind of at a loss. Model class Favorite(models.Model): # key should be

问题 I have got a literal control on page (with some data on it). i want to access it in javascript and want to put some text on it. please tell me how can i access literal control in JavaScript. I was trying with following code- <asp:Literal ID="lblPerInstanceListing" runat="server"></asp:Literal> Javascript: var value= document.getElementById('<%=lblPerInstanceListing.ClientID %>') I am getting null value return by this. 回答1: An ASP.NET Literal control does not by itself insert any HTML into a