[C++]std::mapに[]でアクセスする場合の作用について#include <stdio.h> #include <map> #include <chrono> using namespace std; int getGood(map<int,int> &m, int key, int default_value) { auto found = m.find(key); if(found == end(m)) { return default_value; } return found->second; } int getBad(map<int,int> &m, int key, int default_value) { if(m.find(key) == end(m)) { return default_value; } return m[key]; } int insertGood(map<int,int> &m, int key, int
![[C++]std::mapに[]でアクセスする場合の作用について](https://cdn-ak-scissors.b.st-hatena.com/image/square/5164aa391b2adf672eda4057676b08488a608721/height=288;version=1;width=512/https%3A%2F%2Fres.cloudinary.com%2Fzenn%2Fimage%2Fupload%2Fs---1ZolWF5--%2Fc_fit%252Cg_north_west%252Cl_text%3Anotosansjp-medium.otf_55%3A%25255BC%25252B%25252B%25255Dstd%25253A%25253Amap%2525E3%252581%2525AB%25255B%25255D%2525E3%252581%2525A7%2525E3%252582%2525A2%2525E3%252582%2525AF%2525E3%252582%2525BB%2525E3%252582%2525B9%2525E3%252581%252599%2525E3%252582%25258B%2525E5%2525A0%2525B4%2525E5%252590%252588%2525E3%252581%2525AE%2525E4%2525BD%25259C%2525E7%252594%2525A8%2525E3%252581%2525AB%2525E3%252581%2525A4%2525E3%252581%252584%2525E3%252581%2525A6%252Cw_1010%252Cx_90%252Cy_100%2Fg_south_west%252Cl_text%3Anotosansjp-medium.otf_37%3ANariaki%252520Iwatani%252Cx_203%252Cy_121%2Fg_south_west%252Ch_90%252Cl_fetch%3AaHR0cHM6Ly9zdG9yYWdlLmdvb2dsZWFwaXMuY29tL3plbm4tdXNlci11cGxvYWQvYXZhdGFyLzczMTQ5MmZhZDcuanBlZw%3D%3D%252Cr_max%252Cw_90%252Cx_87%252Cy_95%2Fv1627283836%2Fdefault%2Fog-base-w1200-v2.png)
