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How can I determine whether a 2D Point is within a Polygon?
...hat can handle all three cases above and is still pretty fast is named ray casting. The idea of the algorithm is pretty simple: Draw a virtual ray from anywhere outside the polygon to your point and count how often it hits a side of the polygon. If the number of hits is even, it's outside of the pol...
hash function for string
...e_t m = 0x5bd1e995;
size_t hash = seed ^ len;
const char* buf = static_cast<const char*>(ptr);
// Mix 4 bytes at a time into the hash.
while (len >= 4)
{
size_t k = unaligned_load(buf);
k *= m;
k ^= k >> 24;
k *= m;
hash *= m;
hash ^= k;
buf += 4...
Java JUnit: The method X is ambiguous for type Y
...tages:
Compares floating point values as they are supposed to
No need to cast, as the three argument assert only applyes to doubles, not to generic Objects
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How to convert timestamp to datetime in MySQL?
... seems clear to compare a unix time from a unix time. I use SELECT (CAST(DATE_FORMAT(from_unixtime(UNIX_TIMESTAMP(CURRENT_TIMESTAMP)), '%Y-%m-%d') as DATE) < CAST('2019-05-02' AS DATE)) ; to compare dates, I replace 2019-05*02 a formatted datetime object in php. Thnaks.
...
Multi-statement Table Valued Function vs Inline Table Valued Function
...ke 'C_______' then the outer query did a sub-string and int conversion. ie Cast(Substring(2, 2) as int) as CompNo. All looks good except that sql server decided to put my Cast function before the results were filtered and so I get a mind scrambling conversion error. A multi statement table functio...
Enable 'xp_cmdshell' SQL Server
...ncedOptions int
declare @prevXpCmdshell int
select @prevAdvancedOptions = cast(value_in_use as int) from sys.configurations where name = 'show advanced options'
select @prevXpCmdshell = cast(value_in_use as int) from sys.configurations where name = 'xp_cmdshell'
if (@prevAdvancedOptions = 0)
begin...
Why is conversion from string constant to 'char*' valid in C but invalid in C++
...ion has been removed, an explicit conversion still works, so you can add a cast. I would not, however, consider this "fixing" the code.
Truly fixing the code requires changing the type of the pointer to the correct type:
char const *p = "abc"; // valid and safe in either C or C++.
As to why it w...
How to use Class in Java?
...is overriding the T declared at Class level;
//So There is no ClassCastException though a is not the type of T declared at MyClass<T>.
private <T> T myMethod1(Object a){
return (T) a;
}
//Runtime ClassCastException will be thrown if a is ...
Why should I care that Java doesn't have reified generics?
...
Type safety comes to mind. Downcasting to a parametrized type will always be unsafe without reified generics:
List<String> myFriends = new ArrayList();
myFriends.add("Alice");
getSession().put("friends", myFriends);
// later, elsewhere
List<Frien...
How do I split a string so I can access item x?
...
)
returns table
AS
return (
with tokens(p, a, b) AS (
select
cast(1 as bigint),
cast(1 as bigint),
charindex(@separator, @str)
union all
select
p + 1,
b + 1,
charindex(@separator, @str, b + 1)
from tokens
where b > 0
)
sele...