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How to convert a number to string and vice versa in C++
...o-number conversion and vice-versa are built in into the standard library. All the following functions are present in <string> (as per paragraph 21.5).
string to numeric
float stof(const string& str, size_t *idx = 0);
double stod(const string& str, size_t *id...
Where can I view Tomcat log files in Eclipse?
... "Arguments" tab of its launch configuration:
-Dcatalina.base="${project_loc}\<apache-tomcat-5.5.23_loc>"
-Dcatalina.home="${project_loc}\<apache-tomcat-5.5.23_loc>"
-Djava.util.logging.config.file="${project_loc}\<apache-tomcat-5.5.23_loc>\conf\logging.properties"
-Djava.uti...
What is the difference between C, C99, ANSI C and GNU C?
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Everything before standardization is generally called "K&R C", after the famous book, with Dennis Ritchie, the inventor of the C language, as one of the authors. This was "the C language" from 1972-1989.
The first C standard was released 1989 nationally in USA, ...
What are the downsides to using Dependency Injection? [closed]
...
A couple of points:
DI increases complexity, usually by increasing the number of classes since responsibilities are separated more, which is not always beneficial
Your code will be (somewhat) coupled to the dependency injection framework you use (or more generally how you ...
Which is best way to define constants in android, either static class, interface or xml resource?
... advantages of using project resources is the ease of access and that they allow you to organize your project significantly.
static final constants are compiled into the java bytecode; project resources are compiled into a binary format within the apk. Accessing either is extremely efficient... if ...
Entity Framework: There is already an open DataReader associated with this Command
I am using Entity Framework and occasionally i will get this error.
17 Answers
17
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Disable a Button
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I also get an error if I change (_ sender: ) to UIButton . The error reads: Value of type '(UIButton) -> ()' has no member 'isEnabled'
– user9470831
Feb 5 '19 at 4:25
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dplyr: “Error in n(): function should not be called directly”
...ction" specification, like example below:
delay <- dplyr::summarise(by_tailnum,
count = n(),
dist = mean(distance, na.rm = TRUE),
delay = mean(arr_delay, na.rm = TRUE))
share
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improv...
How to add items to a spinner in Android?
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While this may theoretically answer the question, it would be preferable to include the essential parts of the answer here, and provide the link for reference.
– Bill the Lizard
Jan 26 '12 at 21:00
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E11000 duplicate key error index in mongodb mongoose
... null value.
In other words, a sparse index is ok with multiple documents all having null values.
sparse indexes
From comments:
Your error says that the key is named mydb.users.$email_1 which makes me suspect that you have an index on both users.email and users.local.email (The former being old an...