Odd syntax in C++: return { .name=value, ... } -

while reading article, came across following function:

solidcolor::solidcolor(unsigned width, pixel color)   : _width(width),     _color(color) {}  __attribute__((section(".ramcode"))) rasterizer::rasterinfo solidcolor::rasterize(unsigned, pixel *target) {   *target = _color;   return {     .offset = 0,     .length = 1,     .stretch_cycles = (_width - 1) * 4,     .repeat_lines = 1000,   }; } 

what author doing return statement? haven't seen before, , not know how search it... valid plain c too?

edit: link original article

this isn't valid c++.

it's (sort of) using couple features c known "compound literals" , "designated initializers", few c++ compilers support extension. "sort of" comes fact legitimate c compound literal, should have syntax looks cast, you'd have like:

return (rasterinfo) {     .offset = 0,     .length = 1,     .stretch_cycles = (_width - 1) * 4,     .repeat_lines = 1000,   }; 

regardless of difference in syntax, however, it's creating temporary struct members initialized specified in block, equivalent to:

// possible definition of rasterinfo  // (but real 1 might have more members or different order). struct rasterinfo {     int offset;     int length;     int stretch_cycles;     int repeat_lines; };  rasterinfo rasterize(unsigned, pixel *target) {      *target = color;     rasterinfo r { 0, 1, (_width-1)*4, 1000};     return r; } 

the big difference (as can see) designated initializers allow use member names specify initializer goes member, rather depending solely on order/position.