0.9.9/api/a00311_source.html

 #pragma once
 #include "../detail/type_vec2.hpp"

 namespace glm
 {

     typedef vec<2, float, highp>        highp_vec2;

     typedef vec<2, float, mediump>      mediump_vec2;

     typedef vec<2, float, lowp>         lowp_vec2;

 }//namespace glm
glm::lowp_vec2
vec< 2, float, lowp > lowp_vec2
2 components vector of low single-qualifier floating-point numbers.
Definition: vector_float2_precision.hpp:28

glm::highp_vec2
vec< 2, float, highp > highp_vec2
2 components vector of high single-qualifier floating-point numbers.
Definition: vector_float2_precision.hpp:16

glm::mediump_vec2
vec< 2, float, mediump > mediump_vec2
2 components vector of medium single-qualifier floating-point numbers.
Definition: vector_float2_precision.hpp:22

glm
Definition: common.hpp:20