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insert vs emplace vs operator[] in c++ map
...will overwrite the previous value if one exists.
– dk123
Sep 30 '13 at 9:47
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What is a reasonable code coverage % for unit tests (and why)? [closed]
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GishuGishu
123k4545 gold badges214214 silver badges294294 bronze badges
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String concatenation in Ruby
...; but that is not the usual way
With string interpolation
source = "#{ROOT_DIR}/#{project}/App.config"
with +
source = "#{ROOT_DIR}/" + project + "/App.config"
The second method seems to be more efficient in term of memory/speed from what I've seen (not measured though). All three methods will...
A simple explanation of Naive Bayes Classification
...sitive =
Prob(Test is positive|Disease) * P(Disease)
_______________________________________________________________
(scaled by) Prob(Testing Positive, with or without the disease)
Now, all this was just preamble, to get to Naive Bayes.
Getting to Naive Bayes'
So far, ...
How to properly assert that an exception gets raised in pytest?
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pytest.raises(Exception) is what you need.
Code
import pytest
def test_passes():
with pytest.raises(Exception) as e_info:
x = 1 / 0
def test_passes_without_info():
with pytest.raises(Exception):
x = 1 / 0
def test_fails():
with pytest.raises(Exception) as e_info:
...
计算统计特征（正态分布）函数及实例 - C/C++ - 清泛网 - 专注C/C++及内核技术
...实例main函数：#include "stdafx.h"#include "stdev.h"#include <map>int _tmain(int argc, _TCHAR* argv[]){std::map<int, int> map_...main函数：
#include "stdafx.h"
#include "stdev.h"
#include <map>
int _tmain(int argc, _TCHAR* argv[])
{
std::map<int, int> map_test;
map_test[0] = 100;...
C++ preprocessor __VA_ARGS__ number of arguments
...re however you have a macro implementation that does the count:
#define PP_NARG(...) \
PP_NARG_(__VA_ARGS__,PP_RSEQ_N())
#define PP_NARG_(...) \
PP_ARG_N(__VA_ARGS__)
#define PP_ARG_N( \
_1, _2, _3, _4, _5, _6, _7, _8, _9,_10, \
_11,_12,_13,_14,_15,_16,_17,_18,_...
Optional Parameters with C++ Macros
...id PrintString(const char* message, int size, int style)
{
}
#define PRINT_STRING_1_ARGS(message) PrintString(message, 0, 0)
#define PRINT_STRING_2_ARGS(message, size) PrintString(message, size, 0)
#define PRINT_STRING_3_ARGS(message, size, style) PrintString(message, size, styl...
Overloading Macro on Number of Arguments
...
Simple as:
#define GET_MACRO(_1,_2,_3,NAME,...) NAME
#define FOO(...) GET_MACRO(__VA_ARGS__, FOO3, FOO2)(__VA_ARGS__)
So if you have these macros:
FOO(World, !) # expands to FOO2(World, !)
FOO(foo,bar,baz) # expands to FOO3(foo,bar...
What is the most efficient/elegant way to parse a flat table into a tree?
...e Pitfalls of Database Programming.
CREATE TABLE ClosureTable (
ancestor_id INT NOT NULL REFERENCES FlatTable(id),
descendant_id INT NOT NULL REFERENCES FlatTable(id),
PRIMARY KEY (ancestor_id, descendant_id)
);
Store all paths in the Closure Table, where there is a direct ancestry from o...