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What is Scala's yield?
...I use yield instead of map? This map code is equivalent val res = args.map(_.toUpperCase) , right?
– Geo
Jun 27 '09 at 12:23
4
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Unique fields that allow nulls in Django
...pty string by providing your own customized model form for Foo with a clean_bar method that turns the empty string into None:
class FooForm(forms.ModelForm):
class Meta:
model = Foo
def clean_bar(self):
return self.cleaned_data['bar'] or None
class FooAdmin(admin.ModelAdmin...
Where is the Keytool application?
...achine, you would normally find the jdk at
C:\Program Files\Java\jdk1.8.0_121\bin
It is used for managing keys and certificates you can sign things with, in your case, probably a jar file.
If you provide more details of what you need to do, we could probably give you a more specific answer.
...
How can I maximize a split window?
...l T) to move any open window to its own tab.
As mentioned by others Ctrl+W_ / Ctrl+W| to maximize within the current tab/window layout (while respecting min height/width settings for various other windows).
(Ctrl+W= resizes all windows to equal size, respecting the minimum height/width settings)
...
When would anyone use a union? Is it a remnant from the C-only days?
...For example, let's say you want to create your own Variant type:
struct my_variant_t {
int type;
union {
char char_value;
short short_value;
int int_value;
long long_value;
float float_value;
double double_value;
void* ptr_value;
}...
Deciding between HttpClient and WebClient
... answered Feb 5 at 0:37
Simon_WeaverSimon_Weaver
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...
How to check whether a string is Base64 encoded or not
... for PHP5
//where $json is some data that can be base64 encoded
$json=some_data;
//this will check whether data is base64 encoded or not
if (base64_decode($json, true) == true)
{
echo "base64 encoded";
}
else
{
echo "not base64 encoded";
}
Use this for PHP7
//$strin...
hidden symbol ... is referenced by DSO 剖析 - C/C++ - 清泛网 - 专注C/C++及内核技术
...因是符号(函数)未导出导致的，添加导出申明即可解决：__attribute__ ((visibility("default")) DSO 是动态共享对象，Linux报“hidden symbol ... is referenced by DSO”错误的原因是符号(函数)未导出导致的，添加导出申明即可解决：
__attribute__ (...
C++简练易用的线程池(threadpool)及上下文隔离的无锁线程池(isolated_threa...
...易用的线程池(threadpool)及上下文隔离的无锁线程池(isolated_threadpool)完整实现本文主要介绍两种C++线程池模型完整代码，经过实战考验的，效率已极致优化的代码，可直接用于实际项目开发。1、C++简练易用的线程池(threadpool)
完整...
select and update database record with a single queryset
...
Use the queryset object update method:
MyModel.objects.filter(pk=some_value).update(field1='some value')
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