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C++ equivalent of java's instanceof
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Try using:
if(NewType* v = dynamic_cast<NewType*>(old)) {
// old was safely casted to NewType
v->doSomething();
}
This requires your compiler to have rtti support enabled.
EDIT:
I've had some good comments on this answer!
Every time you need...
How can I check if a View exists in a Database?
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FOR SQL SERVER
IF EXISTS(select * FROM sys.views where name = '')
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How can I output the value of an enum class in C++11
...ts integer value. You need to explicitly convert it to an integer using a cast:
std::cout << static_cast<std::underlying_type<A>::type>(a) << std::endl;
You may want to encapsulate the logic into a function template:
template <typename Enumeration>
auto as_integer(...
How can I convert a std::string to int?
...stinguish between bad input (see here).
4. Fourth option: Boost's lexical_cast
#include <boost/lexical_cast.hpp>
#include <string>
std::string str;
try {
int i = boost::lexical_cast<int>( str.c_str());
float f = boost::lexical_cas...
How do I convert an object to an array?
...Single-dimensional arrays
For converting single-dimension arrays, you can cast using (array) or there's get_object_vars, which Benoit mentioned in
his answer.
// Cast to an array
$array = (array) $object;
// get_object_vars
$array = get_object_vars($object);
They work slightly different fro...
Random float number generation
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This will generate a number from 0.0 to 1.0, inclusive.
float r = static_cast <float> (rand()) / static_cast <float> (RAND_MAX);
This will generate a number from 0.0 to some arbitrary float, X:
float r2 = static_cast <float> (rand()) / (static_cast <float> (RAND_MAX/X));...
T-SQL stored procedure that accepts multiple Id values
...nguages only.
XML. Very good for inserting many rows; may be overkill for SELECTs.
Table of Numbers. Higher performance/complexity than simple iterative method.
Fixed-length Elements. Fixed length improves speed over the delimited string
Function of Numbers. Variations of Table of Numbers and fixed...
C# 'is' operator performance
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Using is can hurt performance if, once you check the type, you cast to that type. is actually casts the object to the type you are checking so any subsequent casting is redundant.
If you are going to cast anyway, here is a better approach:
ISpecialType t = obj as ISpecialType;
if (t ...
How can I truncate a double to only two decimal places in Java?
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If, for whatever reason, you don't want to use a BigDecimal you can cast your double to an int to truncate it.
If you want to truncate to the Ones place:
simply cast to int
To the Tenths place:
multiply by ten
cast to int
cast back to double
and divide by ten.
Hundreths place
mult...
Automating the InvokeRequired code pattern
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Create a ThreadSafeInvoke.snippet file, and then you can just select the update statements, right click and select 'Surround With...' or Ctrl-K+S:
<?xml version="1.0" encoding="utf-8" ?>
<CodeSnippet Format="1.0.0" xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnip...