История изменений

Читните первоисточник, т.е. страусятину.

Stroustroup, The C++ Programming Language, 4ed.

Initialization using {} , list initialization, does not allow narrowing

char c4 {24}; // OK: 24 can be represented exactly as a char
char c5 {264}; // error (assuming 8-bit chars): 264 cannot be represented as a char
int x4 {2.0}; // error : no double to int value conversion

...

There is no advantage to using {} initialization, and one trap, when using auto to get the type determined by the initializer. The trap is that if the initializer is a {} -list, we may not want its type deduced (§6.3.6.2). For example:

auto z1 {99}; // z1 is an initializer_list<int>
auto z2 = 99; // z2 is an int

So prefer = when using auto .

...

The empty initializer list, {} , is used to indicate that a default value is desired. For example:

int x4 {}; // x4 becomes 0
double d4 {}; // d4 becomes 0.0
char∗ p {};  // p becomes nullptr
vector<int> v4{}; // v4 becomes the empty vector
string s4 {}; // s4 becomes ""

Читните первоисточник, т.е. страусятину.

Stroustroup, The C++ Programming Language, 4ed.

Initialization using {} , list initialization, does not allow narrowing

...

There is no advantage to using {} initialization, and one trap, when using auto to get the type determined by the initializer. The trap is that if the initializer is a {} -list, we may not want its type deduced (§6.3.6.2). For example:

auto z1 {99}; // z1 is an initializer_list<int>
auto z2 = 99; // z2 is an int

So prefer = when using auto .

...

The empty initializer list, {} , is used to indicate that a default value is desired. For example:

int x4 {}; // x4 becomes 0
double d4 {}; // d4 becomes 0.0
char∗ p {};  // p becomes nullptr
vector<int> v4{}; // v4 becomes the empty vector
string s4 {}; // s4 becomes ""

Stroustroup, The C++ Programming Language, 4ed.

Initialization using {} , list initialization, does not allow narrowing

...

There is no advantage to using {} initialization, and one trap, when using auto to get the type determined by the initializer. The trap is that if the initializer is a {} -list, we may not want its type deduced (§6.3.6.2). For example:

auto z1 {99}; // z1 is an initializer_list<int>
auto z2 = 99; // z2 is an int

So prefer = when using auto .

...

The empty initializer list, {} , is used to indicate that a default value is desired. For example:

int x4 {}; // x4 becomes 0
double d4 {}; // d4 becomes 0.0
char∗ p {};  // p becomes nullptr
vector<int> v4{}; // v4 becomes the empty vector
string s4 {}; // s4 becomes ""