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What does = +_ mean in JavaScript
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r = +_;
+ tries to cast whatever _ is to a number.
_ is only a variable name (not an operator), it could be a, foo etc.
Example:
+"1"
cast "1" to pure number 1.
var _ = "1";
var r = +_;
r is now 1, not "1".
Moreover, according to the M...
How do I get around type erasure on Scala? Or, why can't I get the type parameter of my collections?
...les above, doesn't the unchecked part in front of the guard condition do a cast? Wouldn't you get a class cast exception when going through the matches on the first object that cant' be cast to a string?
– Toby
Aug 28 '15 at 10:32
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Get int value from enum in C#
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Just cast the enum, e.g.
int something = (int) Question.Role;
The above will work for the vast majority of enums you see in the wild, as the default underlying type for an enum is int.
However, as cecilphillip points out, enum...
Does the 'mutable' keyword have any purpose other than allowing the variable to be modified by a con
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Without the mutable keyword you will eventually be forced to use const_cast to handle the various useful special cases it allows (caching, ref counting, debug data, etc.). Unfortunately const_cast is significantly more destructive than mutable because it forces the API client to destroy the cons...
How to convert a number to string and vice versa in C++
...ingstream with std::ostrstream. The latter is deprecated
Use boost lexical cast. If you are not familiar with boost, it is a good idea to start with a small library like this lexical_cast. To download and install boost and its documentation go here. Although boost isn't in C++ standard many librarie...
C++实现一款简单完整的聊天室服务器+客户端 - C/C++ - 清泛网 - 专注C/C++及内核技术
C++实现一款简单完整的聊天室服务器+客户端Linux下select函数实现的聊天服务器消息缓冲区类MessageBuffer，接收线程将受到的消息放入缓冲区，发送线程从缓冲区中取出消息MessageBuffe...目录：
Linux下select函数实现的聊天服务器
基...
ArrayList vs List in C#
... is a generic class. It supports storing values of a specific type without casting to or from object (which would have incurred boxing/unboxing overhead when T is a value type in the ArrayList case). ArrayList simply stores object references. As a generic collection, List<T> implements the gen...
Postgres: SQL to list table foreign keys
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You can do this via the information_schema tables. For example:
SELECT
tc.table_schema,
tc.constraint_name,
tc.table_name,
kcu.column_name,
ccu.table_schema AS foreign_table_schema,
ccu.table_name AS foreign_table_name,
ccu.column_name AS foreign_column_nam...
How do I write a short literal in C++?
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((short)2)
Yeah, it's not strictly a short literal, more of a casted-int, but the behaviour is the same and I think there isn't a direct way of doing it.
That's what I've been doing because I couldn't find anything about it. I would guess that the compiler would be smart enough to c...
Enum String Name from Value
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You can convert the int back to an enumeration member with a simple cast, and then call ToString():
int value = GetValueFromDb();
var enumDisplayStatus = (EnumDisplayStatus)value;
string stringValue = enumDisplayStatus.ToString();
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