how to make command substitution in fish shell? -

in bash or zsh can write

clang++ main.cpp -g -o bin/main `pkg-config --cflags --libs opencv` 

how can translate fish shell?

fish uses parenthesis command substitutions.

clang++ main.cpp -g -o bin/main (pkg-config --cflags --libs opencv) 

note parenthesis nest nicely, unlike backticks!